dolomiah wrote:
Well I also don't wish to go too far off topic, but it's your thread so I hope you don't mind me indulging a little more on the video generation point.
Nah, a little OT isn't going to bother me.
dolomiah wrote:
I have a bit banged SPI interface through a 65c22 to drive my SD Card for mass storage. SD cards are definitely not very 80's!
Oh yeah, I understand what you mean. I mean, if you want to be 100% authentic retro, then we should be using NMOS, DRAM, etc. But as much as I love retro computers (I have over 60 of them), some of the common annoyances are storage, video, etc. So it's "OK", in my opinion, to mix some modern tech in.
dolomiah wrote:
But if you had a TI994/a (always loved TI's case!), I can see the extra nostalgia of using a TMS9918.
I own 5 (I think) TI's. I have 3 silver ones and 2 tan ones. I love TI. Like I said, it was my first computer. I don't like gutting/modding vintage computers unless it fixes a real problem. Like changing RF to composite. However, I might bend my rule a little with one of my TI's. After seeing the Orwell computer, it reminded me how awesomely retro the TI keyboard is as well. So I may borrow one of my TI's keyboards for my SBC. It's just a keyboard and it's reversible. Oh, and I agree...I love the silver case of the TI. Back in the day when everything was wood grained, TI made their computer metallic. Like they were saying "We're more advanced...we're 16 bit...we're TI".
dolomiah wrote:
The computers I owned as a kid were an Oric-1 (a fairly unpopular machine, 6502 based) and Atari 800XL (awesome machine, especially considering it basically came in to being in 1979). Both of these had custom video, which I could not reuse easily as they were very tied to the machine architectures they were designed for and/or required too much supporting chips and circuitry. Hence I used a TMS9918 because it is basically a standalone device with it's own memory and CRT outputs - it just needs a clock and a bit of interfacing and it works very nicely with non-TI systems (Z80 - MSX, 6502 - My homebrew!).
I would love to have an Oric-1. I love obscure computers too. I even own a Mattel Aquarius in box. hehehe
The video of the Oric-1 would be very easy to reproduce on the Propeller. From what I understand, it wasn't much better than the ULA video of the ZX Spectrum. No sprites. But, it could do two colors per 8x1. I think only the newest Speccy's could do that. So fewer color clashing. That's what is great about the Propeller. If I decide to use it, it would mean a better Propeller programmer than me could upload a new video driver without changing hardware.
As for the 800XL, it's another favorite of mine. I really need to get more into Atari. It's a very underrated system. If you ever get a chance, look for the De Re Atari book. It's amazing. One of the best technical manuals ever. Especially how it explains the GTIA and ANTIC chips of the Atari.
dolomiah wrote:
So to bring back on topic, I am using the 8910 variant as opposed to the 8912. The 8912 has one IO port versus two on the 8910, but still that's ok. Because I interfaced the 8910 through a 6522, commanding the sound chip is a relatively lengthy process (btw the Oric-1 used precisely the same approach as I am using). But I have used one of the 8910 IO ports as a joystick interface, which works a treat. Again, the source code I have posted may help if you're going down the same interfacing route.
That's another interesting point. I'm at a cross-roads with this. So, I have an L-Star that I have tied a 8912 to through a 65C22. Works great. I was writing a VGM player for it and found that it just wasn't working. I will look at your code too and see if there is anything I was missing. But I found that streaming commands to it wasn't working. So I'm really scratching my head on this one.
The second issue with me (hence, the cross-roads) is that I also want to build a Mockingboard clone for my Apple IIe. But, I'd like to do it with the Propeller because I can reduce chip counts. I may be able to do it with no via's and even emulate a SID for the Apple.
I just need to finish one design. The good news is that the Oric-1, the Mockingboard and the L-Star audio card all pretty much drive the AY the same. So a finished design for one takes very little effort to work on another. But do I go 100% retro (65c22 and AY) or modern (Propeller)?
That's the crossroad I'm in.
Which ever I decide, the end result will be the sound system of my SBC. So it's all related. I just can't decide how much retro vs. modern to use.
What would Woz do? LOL