Expanding the IBM 5161 expansion unit

In this video I'm going to max out my IBM 5150 PC and 5161 expansion unit.
I've got a fine selection of expansion cards that I'll be adding to the system including color graphics, memory, compact flash storage, networking, sound, ADC / DAC conversion
Instead of just filling up the unit with useless stuff like 4 COM ports or 3 LPT ports, I wanted for them to actually make sense. So I'm going to go over the different cards, their impact on IRQs , I/O addresses in the machine, and showing them in action.

[@nticompass]

That poor table is struggling to hold that PC and the expansion unit :-O

[@RetroSpector78]

Hehehe ... indeed it is ;) it’s definitely not an XT class certified table .... will have a new dedicated area with bigger , better storage and equipment in a couple of months time.

[@BollingHolt]

... and TWO things I heave learned of today that I didn't know exists: the XT 286 and the 5161 expansion unit! I've also seen the dual displays via the mode command, but I have never seen an application utilize both before. Slick!

[@RetroSpector78]

Bolling Holt hehe .... cool ... make sure to subscribe as I’ll be having lots more IBM related content here.

[@BollingHolt]

@@RetroSpector78 I already have :)

[@GuybrushThriftweed]

They both are not that common indeed. I also learned about these 2 last year and I have them both now.

[@BollingHolt]

@@GuybrushThriftweed I'm going to need another house and another job then because I keep discovering "new" things I want! 😂😂

[@GuybrushThriftweed]

@@BollingHolt yeah it's like a virus. I have around 50 systems (probably more) now and I need to dial it down a bit. My other hobby needs funds too :p

[@GilbertoFerreira]

I am simply addicted to this channel... I just love this kind of old stuff computer, 'cause I grow up messing with 286, 386, 486, both amd and Intel as well... Well done with this channel! Keep it up!

[@RetroSpector78]

Really appreciate the kind words ! Looking forward to bringing some more cool content this year. Glad you are enjoying it.

[@LayneRuley]

This is an awesome video, thank you so much for making content about these older machines! Edit: I love how much detail you go into things like the interrupts. Makes an hardware engineer like myself smile.

[@RetroSpector78]

Cool glad you enjoyed it. It’s a thin line cause you can easily bore people to death with it :) will probably make a more indepth video on it (also putting an AT class machine in the mix). Hope I won’t be boring too many people with this video ... was nice to be able to add all of this stuff in the pc and expansion unit.

[@DFiNEdotnet]

Absolutely loved the video! - And dont worry about how you pronounce things. You are very clear, and easily understood. Keep up the amazing work! Seeing these old machines, and rare expansions, just tickles my nerdy heart :-)

[@kpanic23]

The first Sound Blaster cards were always preconfigured IRQ7. Which is taken by LPT1 on virtually any machine. This doesn't cause any problems, as long as you don't use the parallel port and the sound card at the same time. Which was near impossible using DOS. No game made use of the parallel port, and any program using the printer didn't have sound card support. That's why, when Windows 3.1 came along, sound cards started using their own IRQ5, because now you actually _could_ use the sound card and printer at the same time with Windows multitasking. You could have used IRQ7 shared with LPT1 for the sound card, IRQ2 for the network card and still have IRQ3 free for COM2.

[@RetroSpector78]

True ... wanted to do this by the book :) thinking about going to do a separate video on conflicts and “cheats” like this. If you have more feel free to contact me :)

[@fffUUUUUU]

Afaik game 688 Attack Sub (if I forgot it correctly) is able to use a printer. And it has music too 😁

[@GabrielZ666]

Amazing video from start to end, what a beast of XT setup! I'm new to the channel, loving every video so far!

[@RetroSpector78]

Glad you enjoyed it !

[@junkdata6242]

Wow, this is such a ridiculous setup. I love it ;) Looking forward to a future in-depth video on the 12-bit A/D-D/A card.

[@RetroSpector78]

Yeah that one is definitely coming ! Looking forward to creating that. Arduino style hardware development using gwbasic on an IBM pc :)

[@TheFalschspieler]

Hi, KZbin recommended one of your Videos to me. I really like how you do the Videos, your clear speaking is a blessing! I have subscribed!

[@RetroSpector78]

Thanks a lot ... really appreciate it !

[@osgrov]

Ah, brings back many memories. I remember when that 3com card was new and shiny. Getting old, ack. A delightful video, I can only hope you will do more 80s stuff which is the period I enjoy the most. :)

[@CarlosFBCruz]

Fantastic! Great video. Congrats.

[@DeBovenkamer]

Brilliant! I didn't even know this existed, thanks for that :)

[@christianhalla3905]

The traces in the cga card look awesome

[@CoreyDeWalt]

That thing is awesome! I wish I had one for my IBM PCXT!

[@oso3470]

is amazing. you have treasures in your home. I like to see your video

[@OmegaEnvych]

Ok, this is what I call the Experience. It may not look like much, but goddarn it there was a ton of interesting stuff right here.

[@ropersonline]

17:00: "Now the next card is extremely difficult for me as it contains the number three and I have a tendency to pronounce three as tree." Have you ever lived in Ireland, RetroSpector78?

[@RetroSpector78]

No never ... self-thought English speaking Belgian citizen that missed the subtlety’s between 3 and tree :)

[@ropersonline]

@@RetroSpector78 I see. Well, you're in good company with that "tree" pronunciation regardless. :) From here en.wikipedia.org/wiki/Hiberno-English : "The phonemes /ð/ (as in the) and /θ/ (as in thin) are pronounced uniquely in most Hiberno-English. /ð/ is pronounced as [d] or [d̪], depending on specific dialect; and /θ/ is pronounced as [t] or [t̪]."

[@jamesmcdonough854]

I am impressed you got all of those cards working without any conflicts. my own thought is that when you install cards in a machine like yours it take a little bit of the available ram to make all of those cards work. I don't think loosing ram from 576 to 640 would impact your ability to run software. I recall working in a lab full of machines like this. I had machines withe 5 1/4 inch floppies,. with Hercules graphic cards. I remember we had lotus 123 word perfect and dbase for applications. usually you would put your application in drive a and your save disk in drive b. think it is awesome to see some the these machines get pimped out It was really cool to see the network card stuff I never would have dreamed of back in the day.

[@PavlikoSan]

Ah jumpers, good days!

[@TeslaTales59]

Dual screen for that era! Cool.

[@sgkonfetti]

You can use Turbo Pascal v6.01 with the dual screen setup. Another goodies could be a 8087 coprocessor and a NEC V20. The Nec V20 replaces the 8088.

[@RetroSpector78]

Yep, aware of the V20 but don't have one here ... going to look into the different integrated development environments that runs on this type of system. GWBasic would be time-period correct but the IDE is well .... very very basic :)

[@Inject0r]

Oh man, this is some true hardware pr0n! 😍

[@RetroSpector78]

It is a pretty cool and capable machine now while at its core still an 8088 XT .... not the fastest machine to try all these hardware combinations on :)

[@HudsonGTV]

Now the real question is can you daisy chain more IBM 5161's?

[@timmooney7528]

Expansion cases and expansion packs from that era do not surprise me. The PC Jr, TI99/4a and some other early home computers would have a main "head" option with promise of extra space by way of an expansion chassis.

[@VicGreenBitcoin]

Thanks for this excellent video, Ms.Dos 2.0 or 2.1 can not be used with networks I remember? You needed Ms.Dos 3.0 for that right? How did you do Network with Ms.Dos 2.x?

[@RetroSpector78]

Didn't use ms-dos 2.0. The 10MB hard drive came with ibm dos 2.0 but because that cannot do anything with the xt-ide card I ended up booting msdos 6.22. I think 3.3 would have also worked.

[@VicGreenBitcoin]

@@RetroSpector78 Yes, I see now! Missed the 6,22 part 😳 I have a great Idea, can you connect some old X10 Home Domotica stuff from the 80ies like LGR did :-)

[@RetroSpector78]

Dunno yet ... will need to checkout that video ... don’t wanna just copy something :) will give it my own twist

[@VicGreenBitcoin]

@@RetroSpector78 Yes its must be you own project. However its cool to let your setup do something we can still use today, X10 is perfect for that. What do you think, Will this software run ? www.ebay.com/itm/X-10-Home-Automation-System-Interface-With-Software-And-Connecting-Cable-New-X10/143429370423?hash=item21650e8237:g:auMAAOSwnbZYDYYz

[@VicGreenBitcoin]

@@RetroSpector78 p.s check this: www.investtech.com/nl/market.php?CompanyID=99400001

[@piecaruso97]

The video capture was very good, too bad you don't have an ibm ega card, it whould have been one of the killer updates at the time, together with the extranal floppy drives unit

[@RetroSpector78]

I have an IBM ega card (and also 8 bit ibm vga card) lying here from a friend) that I’ll feature soon, but not on this ibm pc.... would be a bit overkill. Will save it for my IBM AT I think :)

[@tmichiels]

Keigoe bezig!

[@YarisTex]

One good idea would be 4 floppy drives. You could stick a 1.44MB 3.5" drive and maybe a 5.25" 1.2MB drive. You can append Sergey Kisilev's floppy BIOS extensions to the XT-IDE BIOS and have 4 floppy drive support including High Density floppy support.

[@RetroSpector78]

Hehe ... so perhaps I do need to make a part 3 :) Thx for the info ... will look into that.

[@SpookyZalost]

what I wouldn't give for something similar for my modern desktop... needs more expansion cards :P

[@BlackEpyon]

20:58 To understand whether or not you can get a 16-bit card to work on an 8-bit machine, you need to know what the 16-bit portion of the card-edge is for. You can get that by just looking up the ISA slot pinouts. On side "C" (the 16-bit portion of the component side of the card-edge), you see pins C11-C18, and those are for data bits 8-15. But address pins C2-C8 are not populated, which means the address this card uses are all within the first 20 address lines, which means within the first addressable megabyte of memory mapping, and that's all an 8088 processor can access anyways. I don't see C1 populated (system bus high enable), so I don't know if the card shown here is able to tell if data 8-15 are in use or not. Maybe it can tell by whether or not there's data from the bus on pins C11-C18? I'm not sure. On the reverse "D" side, there's pin D2, which is the 16-bit chip select, but after that are pins D3-D7, which are IRQs 10,11,12,15, and 14 in order. That means that whether through software or jumper pins, you CAN NOT assign the card to use those IRQs in an 8-bit system. The last two are +5v and ground, which are also present on the "B" side on the 8-bit portion of the card edge, so they can be ignored.

[@SiD3WiNDR]

Did 1-2-3 also update that secondary monitor graph live when updating data in the worksheet? That would be pretty cool!

[@everyonesloopy]

was there ever an expansion card that could add more IRQs to the system? or are you limited to what the XT has, limiting the amount of expansion cards you can add?

[@RetroSpector78]

You are limited because it is part of the core XT design. Only 1 Programmable Interrupt Controller on the mainboard and only 8 bit ISA slots to expose them to the expansion cards. (the additional IRQs that you get on an AT based system are in the 16 bit part of the ISA slot, so not available on an XT machine. There are lots of expansion cards that don't need an IRQ, and because the XT doesn't do a whole lot of multitasking you can cheat a bit and re-use some IRQs (ex: IRQ 7 from the LPT1 port can be used by another expansion card).

[@xenonkay]

I was kind of surprised you didn't reuse IRQ7 for the sound card as was the norm.

[@Stoney3K]

You could add a Mitsumi CD-ROM drive connected off that Sound Blaster clone.

[@RetroSpector78]

Yeah, but I do like to keep things somewhat period correct :) But would be a fun experiment. Not sure if the mitsumi driver would work on an xt class machine.

[@rasz]

look at sound card CD-ROM connectors - that is one brilliant ground pin row reuse between flipped Mitsumi and Sony connectors :)

[@janhofmeier9427]

I never saw one MFM Controller serving two Hard Disks, so that would be something new to see. Also a CD-ROM on the SB would be nice. Also you coul ad SCSI for a Scanner or Hard Drives.

[@0311Mushroom]

Is not hard. Remove the resisters on the one in the middle of the chain.

[@eDoc2020]

I'm curious if this would work on AT or newer machines. I'm pretty sure it could but it would be neat to see for real.

[@ricardobornman1698]

Once again proving that IBM made some good stuff. Shame it cost an arm....leg...spleen...kidney and liver. 😌

[@RWL2012]

Will actually watch this tonight, but I haven't seen that variant of those speakers with the slatted grilles before! Do they have the polyester reinforced mid/woofers or just the paper-only ones, do they have the real tweeters or the fakes, and do they have the stronger or weaker amplifier...? :-P And yes, I did see the layout of the PC, expansion unit and monitors in the thumbnail ;-)

[@RetroSpector78]

Hope you enjoyed the video ... got lots of other stuff also so if you feel like binge watching the channel feel free :)

[@TrustNo1sz]

Great Video! I found your channel recently and I am enjoying every single one that I watch. I am currently restoring a Compaq SLT/286. Stuck on a hard drive issue now. By the way, where did you get Checkit in English? I could only find German versions.

[@RetroSpector78]

Thanks a lot .... really glad you enjou the videos ... Have boxes full of floppies and I usually take backups from these old xt hard drives. have it from there... but should not be that hard to find on the internet I think.

[@RetroSpector78]

The compaq portable also looks like a fun machine. I am not that good with portables :) have a couple of old portables but really bad at fixing them. Friend of mine collects really old laptops and is really good at fixing them so he already helped me out with my 2 broken thinkpads.

[@RetroSpector78]

Out of curiosity, how did you find my channel on youtube ? Always wonder how people end up finding smaller channels

[@TrustNo1sz]

@@RetroSpector78 I think it came as recommendation. I follow Adrian Black, the 8 bit guy, Jan beta, LGR among other retro related channels. I hope to be able to upload my 1st video very soon.

[@alexandermirdzveli3200]

What a delight!

[@RetroSpector78]

Thank you sir ... hope you enjoyed the show.

[@alexandermirdzveli3200]

@@RetroSpector78 Oh yes! As a matter of fact, I have enjoyed every single one of your shows after I had discovered your channel. You are doing an amazing job! Thanks!

[@MisterRorschach90]

seeing you basically upgrade the 5161 to be as modern as possible makes me feel bad for daru from steins gate. it probably cost him a crap ton of time and money to get the 5100 up and running fast enough to hack into cern, especially with a fiber optic network.

[@MisterRorschach90]

btw you get a sub. this was a great video.

[@RetroSpector78]

Thanks a lot ! Glad you enjoyed it !

[@BenInSeattle]

Thank you for referencing _“STEINS;GATE”,_ an Anime I hadn't heard of before. I just binged all 25 episodes and it was a lot of fun. I particularly liked how they made retro-computing seem vastly important. *"If* *only* *we* *had* *an* *IBM* *5100,* *we* *could* *save* *the* *world!"* Fun fact I just noticed: if you use the New York Times archive (called "The Times Machine") and look up the September 10, 1975 issue, page 75, you'll see a picture of a man and a woman with an IBM 5100. The woman is using the computer, but the man is standing behind it pouring liquid into beakers like a mad scientist. Both are wearing lab coats. If you've seen _STEINS;GATE,_ it's pretty obvious who the two people are. By the way, the show never explains why its title has a semicolon where grammatically an apostrophe should be. My theory is that they used a semicolon because the IBM 5100 keyboard actually lacks an apostrophe (see for yourself in the picture on Wikipedia).

[@JenniferinIllinois]

You may have set a record for the most ISA cards utilized by an IBM PC. :)

[@RetroSpector78]

Would need to check ... next time I’ll make sure to invite someone from the Guinness Book of Records :)

[@JenniferinIllinois]

@@RetroSpector78 Hehehe...

[@thomasandrews9355]

I recently obtained one for my collection. Has two hard drives. Need to take it apart, just like my r6000 servers

[@BollingHolt]

Hmm... So with the NIC and sound card added, all your interrupts are used. I thought I recalled running a NIC on my 486 with both COM1 (IRQ 4) running my mouse, COM2 (IRQ 3) running my modem, a MediaVision Thunderboard installed for sound, and not having IRQ problems. Does the PC/XT class machines handle some IRQ assignments differently, such as for the hard disk?

[@RetroSpector78]

The XT machine only has half of the IRQs compared to an AT class system, and on both class of machines 2 are already in use.

[@BollingHolt]

@@RetroSpector78 I figured something like that. Thanks!

[@namesolonggood1sgone]

I wonder if you could turn a 5161 into a single board computer if you had an ISA board? I've got a Pentium 200 server based on that architecture now.

[@askhowiknow5527]

I did not know Lotus 1-2-3 could do that!

[@Martin_Skywatcher]

If only I knew sooner about this Checkit software, that would have saved me a lot of headaches trying to get IRQ and DMA settings right by trail and error. Where can I find the English version of it for Dos, the Internet Archive only has a German version.

[@RetroSpector78]

Surprised that this would be so difficult to find. Pretty sure I’ve seen copies floating around the net.

[@Martin_Skywatcher]

Found it after some more googeling.

[@solis1232]

21:46 "Cool thing about these things is that it has a soviet IC, the IN558N"

Do you intend to test some graphics environments to take advantage of the mouse? Would be interesting to see environments like GEM and GEOS running, but I guess you'll need an EMS card.

[@RetroSpector78]

Not a whole lot of graphics environments that would work on this thing I think ... but will do some investigation ... Will probably do 1 more video on it cause then she will need to go and make room for some other projects.

[@GuybrushThriftweed]

@@RetroSpector78 She needs to go???!!!!!

@@RetroSpector78 GEM and GEOS should work on that beauty.

[@0311Mushroom]

@@RetroSpector78 GEOS should work fine. Remember, they also did it on the C64.

[@fffUUUUUU]

12:10 I guess it's due to FAT16 volume format, not a partition info (it wouldn't see the CF partition at all otherwise)

[@PeachIceCreamy]

Hey. What would happen if you had two expansion units, and used two receiver cards in your IBM to connect them both? And what would happen if you tried to daisy chain them instead? Super curious :^)

[@brentboswell1294]

Interrupt exhaustion..The expansion units are so rare that it would be really hard to get two working units in the same room 🤣

[@PeachIceCreamy]

@@brentboswell1294 Lol, I know... Would be super interesting to see though

[@wishusknight3009]

576KB of ram is a limitation of the 5150 64-256k boards. A believe a later bios revision corrected that issue. Also the most you should have on that computer is Dos 5. As it is significantly easier on resources and supports pretty much everything 6.22 does. It also should be fine to configure a sound card to IRQ7 and share with the printer port so long as both are not trying to do something at the same time.

[@RetroSpector78]

Need to look into that. Cause the 5150 was able to work with my xt ide card so I assumed the bios was more up to date. My other 5150 (albeit with a 16-64kb board) and older bios (not supporting xt ide) did work with 640kb ram.

[@wishusknight3009]

@@RetroSpector78 Interesting.... Yeah, I had the same issues with my 256k 5150, 576 was it. I never bothered updating its bios though before I let my friend play about with it.. And all he did was mod the motherboard to put 512kb on board, and he left it at that. As that was enough for his rom burner. Until I go looking for the information again, I am only going to say I am about 75% sure a bios update fixes it.. lol

[@RetroSpector78]

wishus knight will let you know for sure in a future video :)

[@freddyvretrozone2849]

Hi,Excellent, Is it possible that you test my MOD Player on your machine ? It has not been tested on a 5150 so far. By the way, you does not need the Sound Blaster "driver", only add the BLASTER Env variable is needed. You can also add an EMS Card, to have 4Mb of memory added.

[@RetroSpector78]

Sure .. drop me a mail (about section on my channel)

[@freddyvretrozone2849]

@@RetroSpector78 Done, in french as you are from belgium. Good to see another retro PC Fan not far from me (France)

[@maedero05]

Memory lane, XT I configured with EMS memory pushing every chip into it´s socket, MS-Dos configured these to a expanded memory flash drive. SCSI external you also can have a seperate unit with internal SCSI devices like a tape streamer or diskdrive´s or bernouilli drive. Afther my XT I had a 386/486 upgrade system so 286/386 SX I never had much exprerience with, do like those retro experiences; technicaly unaware of knowledge of or experience with electronics repair I enjoy these video´s very much, except I´d like to enjoy these old systems aswell. Pentium era may offer me more with some P1 and a P2 system adjacent SCSI devices, HD, Tapestreamer and some IOMEGA Zip drives !

[@RetroSpector78]

Pentium systems are easy to come by here, and don’t tend to break as much as these old xt’s :) love the iomega zip drives. Use them a lot on xt machines also as a (slow) removable external hard drive.

[@intel386DX]

I have a similar sound blaster clone and it works without drivers, games upports it by default :) you do not have to be natall any drivers at all.

[@RetroSpector78]

I would have also thought that, but had the impression it only worked with the drivers loaded .... will recheck soon.

[@intel386DX]

@@RetroSpector78 yes it does :) I noticed it with Comannder Keen 4 :) the best thing is that you do not waste memory, and as we know the memory in XT is very little :)

[@intel386DX]

@@RetroSpector78 here check my XT Bulgarian clone with Comannder Keen 4 running with music via SB clone :) kzbin.info/www/bejne/aGnNnoKPj5eoe5I

[@dan3a]

I have the same exact speakers

[@RetroSpector78]

A lot of people do :)

[@albertstadt9853]

I'm using them too right now on my main Windows 10 machine!

[@Krynos18]

Someone should really make a sim game that replicates the almost black magic required to make the older computers work. This video could be an example of a playthrough video for something like that.

[@BenInSeattle]

A cut scene would make the 30 minutes slog through the SoundBlaster install program more livable. Unless the programmers decided, for the sake of accuracy, it should actually take 30 minutes and be unskippable...

[@ropersonline]

Could the fact you were only able to configure 576K of conventional RAM be related to you having 56K Hi RAM from B200 to C000h, i.e. 8K less than the 64K difference between 576 and 640K?

[@wishusknight3009]

The 5150 only accepts 576 as usable. That is an inherent limit with its bios if I remember.

[@RetroSpector78]

So many people are telling me. I think I missed that when doing some past research ... do you have a pointer on that somewhere ?

[@wishusknight3009]

@@RetroSpector78 I found this from an IBM doc found online. "(#1209) 256Kb Memory Expansion Option Provides 256Kb of parity-checked random access memory on a 5-inch card. Access time of the memory on the 256Kb Memory Expansion Option card is 290ns and the cycle time is 840ns. This card can be installed in any full-feature slot on the 5150 System Unit. For the 5150, this feature can be installed instead of the 64/256Kb Memory Expansion Option with three 64Kb Memory Module Kits to add 256Kb to the 5150 at a lower cost and/or to be able to use a special-feature instead of a full-feature slot for the additional 256Kb. Limitations: This adapter cannot be installed in the 5161 unit. Maximum: One with one 64/256Kb Memory Expansion Option with 64Kb or 128Kb to provide 576Kb or 640Kb. Field Installation: Yes. Prerequisites: The system unit must be at its maximum memory for this feature to be installed. Customer Setup: Yes. " There is also this mentioned in the same document. "(#6052) IBM 4700 Personal Computer Financial Output Option (No Longer Available as of August 16, 1989) This option allows the attachment of a single Finance Printer from this list using DOS 2.1 or later: 4710 Receipt/Validations Printer 4715 Continuous Forms Printer 4720 Forms/Passbook Printer - Models 1, 2, 3, or 4 The adapter card handles the 4700 loop protocol and data stream to the devices. It supports a single device with one or two logical device addresses. It attaches only devices that adhere to the 4700 Universal Device Processor protocols. Each option contains the Financial Output adapter card, the Financial Output Cable, installation and problem determination procedures, diagnostic diskette, microcode diskette with device drivers and configuration customization, and a microcode users guide. For more information about finance output devices, see 4710, 4715, and 4720 in "Machine" section. Prerequisite: An IBM Personal Computer with 256Kb on system board. Maximum: One. Limitations: The adapter must be installed in the system unit and not in a Expansion Unit. With this adapter installed memory is limited to 576Kb. " www-01.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_sm/0/872/ENUS5150/index.html&request_locale=en Seems like it can only accept memory expansions of limited sizes. And I wonder how that card (and mine for that matter) handled the addressing of memory blocks. What it looks like they are saying is you can have one expansion card of 256k and then a second for 64 or 128... So there may be a way to configure the card into giving the computer different block sizes? I am not sure if I am making any sense here, lol.

[@wishusknight3009]

@@RetroSpector78 More from that document. "(#1003) 64Kb Memory Module Kit (No Longer Available as of January 24, 1989) Provides a 64Kb increment of parity-checked random access memory which may be plugged into sockets on the 5150 system board (Models 104, 114, 164, 174, X14, X64, X74 only) or the 64/256Kb Memory Expansion Option (#1013). The 64Kb Memory Module Kits are sold as small, plug-in circuits with instructions for user installation. Maximum: Up to three 64Kb Memory Module Kit increments may be customer installed on the system board, to provide an additional 192Kb of memory. The 64/256Kb Memory Expansion Option provides 64Kb of memory as standard. Up to three 64Kb Memory Module Kit increments may be customer-installed on a 64/256Kb Memory Expansion Option, to provide an additional 192Kb of memory. Field Installation: Yes. Prerequisites: Available sockets on the 5150 system board or available sockets on a 64/256Kb Memory Expansion Option. Customer Setup: Yes. (#1013) 64/256Kb Memory Expansion Option (No Longer Available as of January 24, 1989) Increments system memory by 64Kb (65,536 bytes) and is easily expandable to 256Kb by plugging in additional increments of 64Kb with 64Kb Memory Module Kits (#1003). The 64/256Kb Memory Expansion Option is packaged as a circuit card designed to plug into one of the 5150's five system expansion slots. Technical Information: Random access memory -- starting address is set by switches -- 250ns access time -- 410ns memory cycle time -- parity checking -- sockets for expansion to 256Kb. Limitations: The 5150 supports a maximum addressable memory of 640K bytes. The combination of the memory installed on the system board, and any installed 64/256Kb Memory Expansion Options, and 64Kb Memory Module Kits must not exceed a total of 640Kb of memory. The 64/256Kb Memory Expansion Option must be installed in the 5150 System Unit and not in a 5161 Expansion Unit. Maximum: A maximum of two 64/256Kb Memory Expansion Options may be installed in a 5150. Field Installation: Yes. Prerequisites: The system board must have 256Kb of memory installed (Models 104, 164, 176 only) before adding any additional memory via memory expansion options. An available system expansion slot is required for each 64/256Kb Memory Expansion Option. Customer Setup: Yes. "

[@wishusknight3009]

Page 13 of this guide also has dip switch settings for installed ram. Not sure if this will help or not. I admit I don't recall ever futzing around with the switches on mine other than to change the video setting to color.... www.nj7p.org/Computers/IBM%20PC/work/OriginalPCReference.pdf

[@BandanazX]

Don't think I didn't notice your hand scanner.

[@RetroSpector78]

Will get its dedicated video ... could not get the software to run (not enough memory)

[@offrails]

I can envision Clint (LGR) doing something like this and then using it to play Commander Keen because in his words, "it greatly amuses me".

[@Stoney3K]

Native Dutch speaker probably? Pronouncing 1,2,3 as "één, twee, boom."

[@RetroSpector78]

haha .... inderdaad ...... dude I promise you I will spend the next days / weeks / months practicing this in front of the mirror till I get it right. I tried soooooo hard to get it right this time :)

[@Arti9m]

Huge thumbs up for trying to be a better video presenter!

[@davidcheinrich]

That Novell card was the key card for a Novell server 2.0a version. That was very early copy protection. without it your Novell server was useless. You would never have used it in an 8086 XT.

[@RetroSpector78]

Yeah like I said I was running out of useful cards at the end :( had a Genius hand scanner card but 576kb of ram apparently wasn’t enough to run the scanner software.

[@Damaniel3]

How do you attach your coax network card to your regular network? All my network cards are twisted pair/RJ-45 so I've never had a chance to play around with coax before.

[@DekaSwan86326]

That's interesting way better than the technology we have now

[@Thelemorf]

How is that better?

[@ecologyzone6768]

very nice video!!! Like and subscribe!!

[@RetroSpector78]

Thanks a lot ... appreciate every sub and every view !

[@msdosm4nfred]

_"640kb ought to be enough for anybody"_ - Bill Gates, 1985

[@brentboswell1294]

How IBM squandered almost half of the 1 MB address space of the 8088 on the BIOS and I/O space is beyond me...The Tandy 2000 could address 768k of RAM!

[@ThunderClawShocktrix]

@@brentboswell1294 and worse the palced it ABOVE the main memory had they put it below that the whole 640k barrier would never have existed

[@0311Mushroom]

That was 10 times the RAM of most systems of the era. And RAM was over $8,500 a megabyte. Not many could afford even 640k.

[@iulianispas8634]

Prince of Persia fist game i ever played

[@ropersonline]

1:42: You know the h is not part of the address, right? You're just pronouncing it h to abbreviate hexadecimal, which is what that signifies, but you knew that, right? Okay, just checking and noting this for the record; don't mind me; carry on.

[@RetroSpector78]

Thank you for that corrective statement. I was aware of it but also understand how my pronunciation of the "h" in that context could lead to some confusion :) Thank you for noticing and making it clear ! Hope you enjoyed the video !

[@GuybrushThriftweed]

Finally..... Zzzzzzzz :)

[@RetroSpector78]

If you’ve got ideas for a final part 3 let me know ... the hard drive was acting up towards the end (like it was acting up when you brought it in :)

[@GuybrushThriftweed]

No you can't have it :p Guess I will need to store it and never use it again to save the HD from dying!!!!

[@RetroSpector78]

Lord Cuntard if you’re just gonna store it and not use it you can just as well store a dead one :) but seriously ... was making that metallic sound towards the end again and didn’t boot from it last time I tried. Will try a LLF. Luckily I have a backup of the data :)

[@GuybrushThriftweed]

@@RetroSpector78 Yup that noise didn't sound healthy. Might need to go down the xt ide path. And it will have a lot of company from my other stored machines :)

[@RetroSpector78]

We need to stumble on a large batch of mfm drives some day. If I do I’ll make sure to get you some.

[@msdosm4nfred]

But can it run Crysis? 😆🤣

[@fffUUUUUU]

But can you run fuck off?

[@GeoStreber]

First or something.

[@RetroSpector78]

That was quick .... Good job sir !

[@ArneRagnarsson]

When people insert flashdisk in retro movies, its time to stop watching.