Geoff Oltmans

I know they are popular, but I'm less enthusiastic about FPGA implementations. They are pretty pricey and they are still an approximation/behavioral model compared with the actual hardware. Any implementation software vs FPGA should be possible with a reasonable level of accuracy with either approach of these old machines with modern general purpose computers. I prefer the cheap option.

Emulation is good (and I am clearly vested in that with ADAMEm) but I agree that I prefer the visceral experience to the more ethereal one that emulation typically provides. But of course at some point some obsolete part will become unobtanium and then you have no choice but emulation or substitution. I am genuinely impressed with those that have substituted new designs for unobtanium. In many ways prototyping new hobby hardware has become easier than ever before in the past. Nostalgia is a harsh mistress. haha

I'd like to have a p-code card in any condition. Preferably working of course. Keeping my eyes open for that. I was thinking a clone of that would be nice.

Chip selects to the RAM, ROM strobing?

How long does it stay in reset at power on before coming out of reset?

My bet would be on the SRAMs as well.

Not yet. I want to clean up a few things before I let loose the floodgates.

Very nice that you fixed something instead of relegating it to the scrap heap. Kudos!

I think in general they were probably used to reduce the complexity of the PCB. Makes for a cheaper PCB if you don't have dedicated ground/power planes.

That's exactly the symptom I had on mine and had to replace the upper DSR rom to fix it.

Does the activity light light up at all? Another idea I have would be to try some of the other cru decoding things like the strobe for motor on (KACLK) and see if the disk drive motor turn on. The motor strobe will run the motor for about 3 seconds longer than the cru but is strobed for the motor. Another thing you can check for CRU bits would be to toggle the DSEL lines. These can be easily checked with a simple multimeter. If you have access to mini memory I think that’s a easier tool to drive this stuff with, but of course you could do the same with XB.

With that in mind you could modify the program to access the upper page ROM and see if you get different results as well.

Ah okay... I missed the linked program. You should see the activity light on the card light up when running that program if it's executing correctly. In my case, the lower page ROM was good (the one with the DSR header that you see in the program output), the upper one however was as yours was, all one value (0s or Fs can't recall now).

Does that select the card using the correct CRU enable bit? Cause otherwise you won't see anything at all.

Same here… had to replace the high bank dsr rom on my floppy controller. Symptom on mine was that the system would hang anytime the system would try to access the floppy drive. I was able to confirm the contents using mini memory with the dsr rom cru selected.

Surely JerryG did this because he preferred to have an actual label on cartridges instead of a torn or missing label.

If memory serves, I think one of the folks that recorded some of this ages ago did so using direct measurements from a live system and an oscilloscope. I’d bet money that there’s a reasonable amount of difference in color from one system and/or VDP to another.

If it helps any, here's the values used by the ADAMEm emulator, and they seem pretty accurate to my eye. /* Several palettes */ byte Palettes[NR_PALETTES][16*3] = { /* Coleco ADAM's TMS9918 palette */ { 0, 0, 0, 0, 0, 0, 71,183, 59, 124,207,111, 93, 78,255, 128,114,255, 182, 98, 71, 93,200,237, 215,107, 72, 251,143,108, 195,205, 65, 211,218,118, 62,159, 47, 182,100,199, 204,204,204, 255,255,255 }, /* Default V9938 palette */ { 0, 0, 0, 0, 0, 0, 32,192, 32, 96,224, 96, 32, 32,224, 64, 96,224, 160, 32, 32, 64,192,224, 224, 32, 32, 224, 96, 96, 192,192, 32, 192,192,128, 32,128, 32, 192, 64,160, 160,160,160, 224,224,224 }, /* TMS9918 Black & White palette */ { 0, 0, 0, 0, 0, 0, 136,136,136, 172,172,172, 102,102,102, 134,134,134, 120,120,120, 172,172,172, 136,136,136, 172,172,172, 187,187,187, 205,205,205, 118,118,118, 135,135,135, 204,204,204, 255,255,255 }, /* V9938 Black & White palette */ { 0, 0, 0, 0, 0, 0, 144,144,144, 195,195,195, 60, 60, 60, 115,115,115, 80, 80, 80, 178,178,178, 102,102,102, 153,153,153, 198,198,198, 211,211,211, 100,100,100, 129,129,129, 182,182,182, 255,255,255 } }; Probably not worth getting too terribly hung up on IMO, since remember TVs of the time had a tint/hue control that could be set to any number of positions by the end user.

I once upon a time stuck a TIM board in my Coleco ADAM and got it to work (that was a strapping option on the TIM board and plans were apparently in place to support the ADAM). The issue is that the 9958 upon initialization has a set of palette registers not found on the 9928/9918 that you have to program for there to be any video output. Otherwise, all output is black on black! I wrote a small program to initialize these registers on the ADAM and it worked. I suspect that's probably all that's in the SOB otherwise you'd likely also get a blank/black screen on the TI.

I have a few: - Over the course of the past year I’ve decided that I have only so many hours in the day and that I should reduce/refine my collection to account for that reality. To that end I’ve decided to cut down the stuff I’ve got. I’m paring the collection to the Coleco Adam, TI 99/4A, Atari 800XL, and Commodore 128D. All of these save for the Atari have personal significance to me as I cut my teeth on them. - Get Adamem SDL in a releasable form (finally). - I feel like we have entered a period of renaissance with classic computers. We are seeing cheap affordable add ons and peripherals for the old machines thanks to the efforts of a few dedicated individuals. Up to now most of my activities (emulator aside) has focused on using old software. I’d like to help with some of these efforts (namely tipi and fujinet).

Ordered a TIPI-PEB... which I have yet to install.

(dupe removed)

Indeed... lately I've been wondering about how hard it would be to do a GPL interpreter for the ADAM. (and...you could probably I'm guessing put a GROM port in IO space on the Z80). I guess the real question is how much "pure" GPL programs there are out there... it seems like a good chunk of the console GROMs for sure unless they reference DSR routines at specific addresses, Car Wars is supposedly 100%, but my knowledge of GPL/GROMs is pretty superficial. It does make me wonder if part of the motivation for GPL was to abstract the hardware design enough that they could change the underpinnings more easily.

To be fair, Wing Commander on an Amiga isn't a particularly great experience either. heh

Would be interesting to see the difference in radiated emissions of the cast cage vs a sheet metal cage. Personally I'm skeptical that they'd be much different.