Tandy 1000 Core

[Awestyn]

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[ExCyber]

Judging by the Wikipedia article, "Tandy 1000" is almost more like a brand than a specific computer. Which models are particularly interesting? I know a bunch of DOS games had a "Tandy 1000" configuration (in the same sense that you'd configure a game for e.g. CGA and Sound Blaster), but I don't know if the common case was the original Tandy 1000 or one of the upgraded models. Early models didn't have an 8237 DMAC, but later models added it. It seems like the base model would be pretty slow with a 4.77 MHz 8088 and no DMA. At the other end of the spectrum, the Tandy 1000 RSX is probably overkill, and I'm not sure it's even compatible with "Tandy 1000" software.

Also, would it make sense to combine this with a PCjr core? Neither platform is a strict clone or superset of the other, but there seems to be a lot of overlap for at least the early Tandy 1000 models, and I seem to remember at least a few games treating them as equivalent.

[yaroze]

I own a Tandy 1000A, which is the original model with a few fixes on the mainboard, and the Tandy 1000 is more PCjr than PC clone, it used the same video and sound hardware as the PCjr, but Tandy, decided to include standard ports (like db9 for video) and ISA slots, whereas the PCjr used sidecar bus that is simular to the ISA bus mostly, and proprietary connectors for the peripheals, my 1000 is stock, except for the add-in cards, there are 3 slots, 1 has the RTC/Ram expansion to 640k, the next slot has a 80286 accelerator, and the 3rd one had the controller for the external 20 meg MFM hdd, well the HDD died, and has been replaced with a ISA IDE Compact Flash solution. The video is digital RGBI like CGA or 80 column mode on a Commodore 128, it is CGA compatible but full 16 color capable, vs 4 at a time like CGA, but not EGA. the "PC" speaker has 3 voices vs the 1 voice beep channel from the IBM PC.

[Awestyn]

The Tandy 1000 was the response to the PCjr. It was considerably more affordable at the time and could run most of the IBM XT software. It was not however identical. There was TGA graphics and Tandy sound, which was way better than any XT computer at the time. It should definitely have it’s own core running an 8088 or 8088-2 with the option to run at 4.77 or 7.16 MHz. Ideally modeled after the 1000 HX or SX.

[rimsky82]

Sorry for the necrobump, but I mentioned this in Discord and just wanted to leave it here.

I would also love to see a Tandy 1000 core, specifically for the EX model. It was my first computer growing up and really stirs the nostalgia feels. I have an extra EX machine, and also another model 1000, I think an HX or an SX that I would be willing to donate to any developer interested in developing a core. I have a couple of the expansions too, including the RAM expansion and something else, though I would probably want those returned to me.

[Pierco]

I started to look at the PCjr schematics and I think most of the HDL modules exist. The problem is the graphic adapter (mc6845), I don't think it has been reversed or implemented and I can't find good documentation about it.

[kathleen]

@Pierco, I cross my fingers hoping that you'll find something regarding the graphic adapter.
The Tandy 1000 (and all the other Tandy's computers including the Coco to be honest) is one of my favorite computer. I still own a Tandy 1000TL and I won't change it for anything else, but if one day a Tandy 1000 core comes out it will be a dream.

[breiztiger]

@pierco : i think that mc6845 is like amstrad cpc crtc perhaps you can take a look

[jordi]

it's worth joining work with this repo?
https://github.com/RW-FPGA-devel-Team/zet_MiSTer

[dmckean]

I hope this core becomes a reality. It would be cool if it was allowed to be booted with either TGA or CGA as some PC/XT games were unable to run in color on the mc6845 graphics and you had to settle using Hercules or something else instead.

[Mills]

I hope this core becomes a reality. It would be cool if it was allowed to be booted with either TGA or CGA as some PC/XT games were unable to run in color on the mc6845 graphics and you had to settle using Hercules or something else instead.

A lot of EGA and VGA software will also work on a tandy 1000, it would be like all purpose XT core, with some ram and graphic options.

[dmckean]

I started to look at the PCjr schematics and I think most of the HDL modules exist. The problem is the graphic adapter (mc6845), I don't think it has been reversed or implemented and I can't find good documentation about it.

I think I found schematics for the Tandy 1000 video logic. I'm not sure how useful they are for you.

https://ia803208.us.archive.org/15/item ... _Tandy.pdf

[macro]

I started to look at the PCjr schematics and I think most of the HDL modules exist. The problem is the graphic adapter (mc6845), I don't think it has been reversed or implemented and I can't find good documentation about it.

bog standard display control chip, used in several machines including commodore PET, BBC, Amstrad 464 and probably many more

http://bitsavers.trailing-edge.com/comp ... s/6845.pdf

[alanswx]

https://github.com/EisernSchild/MC6845

[Tandy]

Would love to see the Tandy 1000 core on the Mister.

[jordi]

Would love to see the Tandy 1000 core on the Mister.

so there it is
viewtopic.php?t=4680&start=630

[somhi]

PCXT core has dual mode: IBM PCXT and Tandy 1000