TMS9918A on 6502

[@berretw]

WOW, great video, I can't wait for the next episode !!!

[@matthewe3813]

A video without a dislike is rare on KZbin.

[@Hardwarenerd]

Simply put "you are awesome man!" I was searching a video output for my current z80 computer... Your two videos are golden along side with the tms9918 manual.. Keep up the good work!!

[@uni-byte]

It's not the delay of the additional NAND, it's that the RAM /CS signal is qualified by the Phi2 clock (CLK). When Phi2 is high, the address lines are stable and teh data is stable when it goes low. That CLK signal you show is the Phi2 clock. If you took that CLK and connected it to pin 6 of the 74LS138 (the positive enable, E3) you would be even better off.

[@cbmeeks]

Can't wait for this series!

[@matthewwallace9686]

Count me in as well 😂

[@NotMarkKnopfler]

This was great. I understood the machine code but I must admit the address decoding lost me, although I do understand the concept. Many thanks for this. Liked and subscribed 👍

[@tylerlatham8784]

I ordered some sound chips and picked one of these up as an impulse. Or so I thought. I got a TMS9928A. I don't have any monitors with YPbPr input so I guess I'm on the market again.

[@MarianoLu]

Great content, keep them coming!

[@Lantertronics]

Did you have to do any particular work into choosing the capacitor values to use with your crystal?

[@krallja]

No, I didn’t - these capacitors were from the kit by Mr. Kamprath. Someone else did the work for me😂

[@Lantertronics]

@@krallja :)

[@Lantertronics]

@@krallja My colors works on some LCDs but not others; on some the colors show up as alternating white black bars in different patterns (like Apple 2 color graphics on a monochrome display). I haven't tried it on an actual CRT yet, because my CRTs are in my office at work, which I can't get to for 8 weeks because of asbestos abatement and roof repairs, ugh...

[@krallja]

@@Lantertronicsthe …peculiar… color burst frequency of this chip means it won’t be 100% compatible with some LCDs framebuffer decoders. a raster display like a CRT or DLP will probably do better

[@lukenaegle5014]

after testing with many caps i found that 33pf worked for me on the crystal

[@TEBLify]

Another great video, you're on a roll! Haven't spent much time with wd65c02, but for the timing - couldn't you feed phi2 into 138 and match it to HI?

[@krallja]

Yes, I believe that's actually the intended use of Phi2. But I already had that NAND so convenient from Ben Eater's videos…

[@TubeNagen]

Hi tebl! Fancy seeing you around. I am running the BE6502 off of your boards! Thank you so much for publishing these. Turns out breadboards don't like me much either. I have the TMS9918 board running and can't wait to see a good integration with the Ben Eater board. Cheers!

[@Lantertronics]

I was going to ask the same question, when I was scrolling through and found yours! Thanks!

[@WaldoHazeleger]

What other chip: SOUND ! (like the YM2149F)

[@garymetheringham4990]

Any chance of sharing the source code you used for both the lcd and tms9918a basic please. i am in the process of building an Eater 6502 with display and have the tms9918a on order

[@krallja]

The TMS9918A source code is on my GitHub, but I haven’t committed BASIC yet. I’d like to do a video series on that… someday…

[@garymetheringham4990]

@@krallja oooh cant wait for that! a detailed explanation of what needs doing to get the core basic runnung would be great. are you adding an ay3 sound chip as that would be handy also

[@kevinhart68]

Great videos. Any plans to continue the series ? - would be good to see the VRAM added + some Patterns / Sprites displayed.

[@krallja]

Thank you! Yes, that’s in work right now. I have the VRAM working and need to finish editing together the video + voiceover footage. Then I’ll program some patterns and sprites, edit that, and post. Stay tuned :-)

[@grulloc]

Is that the BenEater 6502 kit!?

[@krallja]

yep!

[@matthewwallace9686]

Great video, super helpful! Is there anywhere I can find an explanation of your assembly code and the source file?

[@matthewwallace9686]

BTW, the goal of the project i'm working on is to have Ben's 6502 work with the tms9918a, Ben's PS/2 keyboard circuit, and some form of basic. I would like the user to be able to do simple things like look at register data, enter simple commands like add 2+2 and so forth. If you have any advice on how to implement all of these things together I would greatly appreciate it. You've already been an incredible help with your videos!

[@krallja]

@@matthewwallace9686 github.com/InPermutation/be6502/blob/Static_VRAM/vdp.s is the latest version of the VDP control assembly. I’d like to do a series on implementing BASIC some day.

[@matthewwallace9686]

@@krallja I can't put into words how helpful you are lol its amazing

[@matthewwallace9686]

@@krallja does "-- INSERT --" on the program text mark the end of the program?

[@krallja]

@@matthewwallace9686 yes, that’s the status bar of Vim I think

[@edgeeffect]

You've got to get some extra points for pointing out that 6502 is Von Neumann architecture, not like AVR's Harvard architecture. :)

[@HugoSerenoFerreira]

Great work! Please continue the series, and set up a Patreon account if you don't have one :)

[@squirlmy]

All of this is beyond me. I have no idea how to read schematics, for example. To the guy who comments he can't use it for his work: you go to KZbin for work-related things? Weirdo! The video is a great example of an ideal resource I wish I had when I was younger. Too late now though.

[@nathankrall7471]

Well I may have learned something new today but I’m not sure if I can use that in my line of work. So if you’re gonna write computer code then you kinda need to know how your hardware is set up?!? :-)