The Incredible Story of The Little Board That Sparked A New PC Architecture!

[@SteveInScotland]

In my first job in the mid 80’s I used a CP/M machine. It had twin external 5.25 inch drives. We used to, fairly regularly, send it away to be recalibrated otherwise it would drift over time and things would get unreadable. So I fully understand getting your drives calibrated and getting a slip of paper to prove they did something. Lol.

[@nasabear]

I built an Ampro Little Board computer with two half height floppies as my first computer. I connected it to an H-19 terminal I had previously built. I used the terminal to access the University VAX 11/780 through a modem. After I built the Ampro, I was able to use it to access some local BBSs as well. I later passed it down to my dad who used to run some ham radio programs. It was a real work horse for us.

[@RetroHackShack]

Awesome

[@horusfalcon]

H/Z 89 refers to the Heathkit H-89, and the Zenith Z-89 (the pre-assembled "retail" version of the H-89).

[@DC-go5mc]

I built an original Ferguson Big Board system in 1984 with 2x 8" SSDD drives running CP/M 1.4 then 2.2. It had a 300 baud acoustic modem, then I got a "high speed" 1200 baud direct connect Prometheus. Used it calling into bulletin boards and ran Adventure, Zork series, Word Star, VisiCalc, etc. with a dot matrix printer. Used it until I bought a Gateway PC from Best Buy on Black Friday in about 1995. The Ampro "Little Board" was actually a derivative of the Big Board, as were the KayPro, Osborne, and other luggables of the ERA. The worst mistake I ever made was letting my wife talking into trashing that computer.

[@RetroHackShack]

We have all been there. I sold my first computer in a garage sale. 😥

[@miked4377]

what a great video you did here arron!! that ampro is so cool!! and the fact that it works is incredible! I would definitely make an authentic ampro case...and definitely play some games!!!

[@mogwaay]

That's a really interesting find, and really interesting to hear the history of the PC104 standard. Impressive that it just worked after all this time.

[@tekvax01]

DCE and DTE will bite you every time! It's best practice to always use an RS-232 tester with LEDs on every data and sense pin. I have a really nice one from black-box that I still use all the time! It has saved me countless hours in troubleshooting serial connections!

[@RetroHackShack]

I have a black box one as well. It's on eBay. Maybe I should save it.

[@russb257]

Back when I was stationed at Chanute AFB in Rantoul IL about 1986/87 there was a BBS down in Champaign-Urbana that was run on an AmPro Little Board, 2 drives and a VT100 terminal. I havent seen one of those boards since then

[@RetroHackShack]

That's a great use case for this!

[@paulstubbs7678]

I built up an Ampro Z80 system many many years ago, it was intended to be a BBS, however that never happened. Later on the -12V power supply converter module died, and in the end I threw it out. Many years later I worked for a telco in their repair shop, where I scored a pile of PC104 Ampro boards that were used in cable TV scramblers. These boards boot from a eprom that basically has a floppy image burned into it. I succeeded in creating my own eproms running my code.

[@JVHShack]

There's a computer store near me that has a couple of cases that can house 2 half-height 5.25 drives and the have a small power supply in them. Perhaps something like that would suffice? They are all black, but maybe taking a page from LGR's book would do the trick? There were black faced electronics with a woodgrain cover in the early to mid-80s.

[@CharlesOttman]

The H/Z in the multi format program is Heath/Zenith

[@RetroHackShack]

Of course! I should have remembered that. Thanks!

[@robynr447]

You DID dump the ROM as a first step, right?

[@tiemanowo]

Great idea to preserve them while they are still working.

[@RetroHackShack]

I did check and they are already archived.

[@ardentdrops]

If I find out something I dumped already exists I do a diff on it just in case because I stumbled across a few lost revisions in the past I would have missed otherwise

[@justajeffy]

Every time I have issue with a serial connection, I usually struggle for way too long trying to figure out the problem only to eventually finally swap the cable and have it then work immediately. It's always the cable.. Grrr.

[@wafikiri_]

Once, I had that same problem at work, and swapping the cable didn't solve it because the new cable was faulty too. It took me very long to solve it, so, remember this next time.

[@nevets9436]

I highly recommend you get a greaseweazle to read/write disk images for these old unique cp/m systems. There is also the old dos 22disk program that can read and write a ton of obscure cp/m formats. I checked and it does support the ampro format.

[@RetroHackShack]

I have a greaseweazle, but I will definitely check out 22disk. Thanks for the tip!

[@nevets9436]

@@RetroHackShack You are welcome. Incidentally, I recently acquired a datavue 80-200 z80 based cp/m 2.2 computer from 1982 that is very similar. However, the PCB for it mounts to the bottom of the Tandon floppy drive through long stand offs.

[@joukoforsstrom4697]

Memories from about 40 years ago! I found info about the Little Board from some magazine, maybe Byte. We contacted Ampro and there was talk if they could supply Theos (formerly Oasis) operating system with those boards, so we could build simple and very cheap multi-user machines (2, maybe 3 dumb terminals). Theos was an unbelievably capable OS for Z-80 (later x86) and could really run multi-user business applications. It's a pity the project stalled. But I have fond memories from that time.

[@JamesPotts]

Pins 2 and 3 are swapped on the 9-pin connector. So if 25-2 goes to 9-3, it's actually straight-through, and not crossover.

[@robynr447]

My Best guess is that the printout is a calibration report on this or another similar floppy drive. Cues are the words Read and RW.

[@RetroHackShack]

You got it

[@RacerX-]

That is a great find. This little board computer would be a great candidate for a recreation. The board is small, most of the components are probably still made, including Z80 versions. I would think it wouldn't be very hard to recreate this board in Kicad. I would build one for sure.

[@retroatx]

I think someone did this a couple decades ago with it being small enough to mount on a 3.5" drive but I may be remembering wrong.

[@lonewolf31337]

very cool find. thanks for the awesome video

[@GarryGri]

A genuinely interesting video. Thanks for this.

[@GianmarioScotti]

What's the support for 8" drives, or even for hard-sectored 5.25" setups? What I mean, is there a way to configure this board to support such media?

[@RetroHackShack]

Maybe, but since it came out in 84 probably not as those formats weren't being used as much then.

[@ericblenner-hassett3945]

I have looked into similar boards a few years ago as dedicated boards for a 3D printer. Some of them had 28-24 pin eeprom to store settings instead of needing a battery. Things have changed alot since then thanks to other single board computers.

[@RetroHackShack]

Yeah. The RPi and others have taken over this space for hobbyists at least.

[@wiebel7569]

You should label that a null modem cable and keep it for when you need it.

[@user-yr1uq1qe6y]

I remember early in my career (late 80s), seeing so many interesting embedded and industrial systems that would have benefited from something like this. I can imagine the Raspberry Pi, Nano, and similar x86 based units are designed into systems these days in a similar fashion.

[@mrz80]

Ampro LittleBoard! I ran a BBS on one for a while, then it was my main machine right up thru the early 1990s, when I finally got a decent PC. Still got it tho it hasn't booted in years.

[@RetroHackShack]

Awesome

[@tekvax01]

CP/M long in the tooth in 1983! I don't think so... I was using cp/m well into the early 90s, as were many others!

[@tenmillionvolts]

D25 to D9 is a natural crossover due to the reversing of pin numbers between them. If it crossses 2 to 3 and 3 to 2 on a 25 to 9 cable, that's a straight cable. 2 to 2 and 3 to 3 is a crossover. That could be the issue. It got me the first time I saw it. I had always used 9 to 9 pin cables before that.

[@CayMacVintage]

Great video and amazing device. Love it

[@CayMacVintage]

Corrected the typo.

[@johnn0hj]

What is the tablet you were using here?

[@RetroHackShack]

Asus ROG Flow Z13. It's a beast!

[@AndrewHelgeCox]

Could you put your second channel in a channels tab on this one and in the links in the description for this one please?

[@RetroHenni]

My first guess when seeing this device was, it looks like a selfmade disk copy station.

[@RetroHackShack]

I thought so too

[@Fezzler61]

Very cool.

[@mikehughesdesigns]

They still make RS232 Breakout Boxes...

[@garthhowe297]

Fascinating episode. Hard to believe that ps had perfect regulation after 40 years.

[@RetroHackShack]

I know, right?

[@charleseslick3336]

Try talking to Selby from Tech Tangents about copying CPM files

[@RetroHackShack]

Thanks. I'll check it out.

[@galeng73]

I think I've heard of this before. It reminds me a bit of a modern Raspberry Pi (or similar).

[@RetroHackShack]

Quite similar in some ways

[@galeng73]

@@RetroHackShack I watch a lot of this sort of stuff and you popped up in my feed. So, I'll subscribe to both of your channels. I like interesting content and I was around for those heady days of yore.

[@dcarlin3]

Did you figure out what the switch on the front was for? Great video!

[@RetroHackShack]

Oh. I guess I forgot to show that. It was just used for reset.

[@TomTRobot]

System disks, user's manual, schematic, Z-DOS/ZRDOS, and disassembled listing for your boot ROM all available on Internet Archive. Board definitely has parallel port though it's missing some Centronics signals (see user manual). No non-volatile or RTC. TM100-1 is single sided "180K" drive, TM100-2 is a double-sided, double density "360K". Oddly it looks like your drive has connectors for two heads (connectors 3 and 4 toward from of drive). Typically a single sided drive will only have one. Ampro format actually puts an extra 512 byte sector on each track, yielding 400K on a "360K" drive. TM100-2A is basically same Tandon drive IBM used on original IBM PC, though with IBM logo on faceplate. The best compatibility will be with a real 360K double-sided drive. Some of the Ampro images may be double-sided images. You can use 1.2M drives but only formatted as "720K" (800K Ampro format). The floppy controller on the original Little Board can handle double-density (2D / DD) but cannot handle the HD speed of 1.2M floppies.

[@TomTRobot]

BTW: Where did you find your Ampro company history info?

[@RetroHackShack]

Cool. Thanks for the info.

[@RetroHackShack]

Various places. There have been several articles written about the history of the founders over the years.

[@AdamKlein77]

Is the drive not an Apple Disk II? Sure looks like it.

[@RetroHackShack]

Nope. I think those were shugart SA390 mechanisms with Woz guts in them.

[@AdamKlein77]

@@RetroHackShack I'm pretty sure they were more or less the bare drives, minus the Shugart controller (b/c they Wozzed their own). The case looked uncannily familiar.

[@jescis]

That's pretty neat!! I wish I could get one… for cheap 😁😁

[@lorensims4846]

The fact that it has a 5 1/4" floppy drive tells me it's probably from the early to mid-'80s. Before 1980, 8" floppy drives were more common. Also, there were not many DIY computers with any kind of mass storage in the '70s. Tandon 5 1/4" drives date from 1979.

[@solzarcat555]

@ 5:42 not gonna lie I have no idea what it is. xD pretty good video so far

[@sarreqteryx]

H/Z = Heath/Zenith?

[@bokami3445]

Putty, The replacement for Telix :-)

[@igorperuchi2114]

Nice video featuring a nice machine! As we could see, SBC's are nothing new!

[@Vermilicious]

Cool.

[@richfiles]

Man... I _WISH_ my area Craigslist had vintage computer stuff like this... Where I live, no such luck... Corn and soybean fields as far as the eye can see in the warm seasons, dirt and snow when it's cold. Such a bore here... Least it's cheap.

[@derekchristenson5711]

Cool!

[@SimonEllwood]

A good video but your understanding of RS232/V24 and pre PC disk drives is a little lacking. I am guessing luckily for you you are not as old as me. All the best.

[@andydelle4509]

If serital hardware handshake is being used, then the handshake signals must be crossed as well in a null modem cable. I hate old school hardware handshaking!

[@coryengel]

SO SICK OF PCB WAY ADVERTS

[@rootbeer666]

Would you rather like VPN ads instead? Or Shadow Legends or whatever that game is called?

[@sparthir]

So sick of people moaning about adverts that are at least a little related to the content.

[@mstandish]

The nerve of people wanting to be paid for their time. Skip the AD if you don't like it.

[@slightlyevolved]

I'll take them any day over RAID SHADOW BUG SPRAY. PCBWay at least has a history of being useful, reasonable, and not trying to control the content of the channels they contract with.