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fabrice montupet

Cards and other expansions I made for TI-99

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Here is a Multifunction card that I made for the 99/4A, I realized it two years ago.
Its features: 32KB expansion RAM, Speech Synthesizer, Audio Amp, Real Time Clock and analog I/O port.

ti99_multifunction_card.jpg
I will show here you some other cards/expansions I made for the TI

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Thank you all for the compliments!

Of course, this card can be reproduced, before I must gather all the notes and schematics I made.
I used the I/O analog ports to capture photodiodes, it was fun :-)

Here is the Hexbus drive controller that I made to be able to use programs on my 99/2, 99/5 and 99/8 computers. The dump of the 99/5 has been made possible thanks to it.
For the case, I used the metal case of two D2 SCSI jaz Drives, I constructed the two plastic front pannels, added braces to fix my PCB, modified the power supply, made the rear connectors, painted the cases in beige (and light purple for the eject buttons) and printed a sticker. Thus, I think that it's style corresponds to what it was done in the 80's, and especially for Hexbus products line.

 

hx5102m_3.jpg

hx5102m_4.jpg

hx5102m_1.jpg

 

hx5102m_2.jpg

Herie is a video of the PCB in action:

http://www.ti99.com/my_projects/HX5102M2.mp4

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Oh my god, i had seen the video before, anyway the final result of the Floppy Disk drives is really professional ! :-o :-o

in addition the color and the sticker match nice with the TI original stuff :)


maybe, you and ksarul might start a nice collaboration for a future production of your stuff Fabrice ! :P
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I already have a pile of photographs from a Hexbus drive, courtesy of Jens-Eike Hartwig. I also have a dump of the "firmware" (ROM) on the drive. What would be particularly interesting are schematics for the drive; this would really be helpful for an emulation in MAME.

 

Anybody to follow the traces on the board? :)

Edited by mizapf

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Thank you again!

 

I'm going to tell you about a rather special project I made this year. It has been initially released for the Apple II but its link to TI is significant because it uses an IC of my favorite VDP family...the TMS-9929.
I have chosen the 9929 because I wanted to use RGB monitor for a bright and sharp display.
At the beginning of the project the master idea was: How offering much more colors and sprites without using a modern and anachronic video electronic part. The solution: Use two VDP on a PCB :-)
So, I cascaded two TMS9929. Result: Two superposed and independant VDP displaying 120 colors and 64 sprites simultaneouly . When I saw the firsts results, I was impressed! Especially as my code was not optimized.
I added to the board a little more by integrating 2 Kb of SRAM (with a CR2032 battery to maintain the memory) which may contain user video routine codes.

A picture of the prototype version:

D-VDP9929A.jpg
And the final version, I named it "ColorSprite+". The PCB Gerber files are done, a production can begin :
ColorSpritePlus-small.jpg

 

For fun, I have decided to realize again this project but now for TI-99/4A... Soon :-) It will come in the form of the PCB that will take place onto the computer motherboard.
At the age of the TI-99/4A, it was possible to make exciting video upgrades :-)

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I like the Colorsprite+ idea a lot, I would love to get on of these if this is realized as a PCB card for the TI-99/4a.

So if I understand you correctly, this project would have been possible back in the old days when the TI-99/4a still ruled the world? Meaning biggest part of the components was available in the 80's ? Cool!

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It was also the goal of this project. only use IC that were available at the time of the 99/4A/ The date codes of all the IC used for my prototype are between 1981 and 1983.

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Great stuff! This is what I like!

 

A bit nicer would be a card with the dual VDP for the PE-Box. What do you think?

Tell us a bit more about your card and the reason to place it in the console. I think that you are intent to place the piggyback board of the prototype into the console, isn't it?

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Oh my god, i had seen the video before, anyway the final result of the Floppy Disk drives is really professional ! :-o :-o

 

Yeah, no kidding!! I'm really impressed with the skill and time Fabrice puts into his projects. Everyone of them is a pure work of art... form and functionality.

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Thank you all for the compliments!

 

Of course, this card can be reproduced, before I must gather all the notes and schematics I made.

I used the I/O analog ports to capture photodiodes, it was fun :-)

 

Here is the Hexbus drive controller that I made to be able to use programs on my 99/2, 99/5 and 99/8 computers. The dump of the 99/5 has been made possible thanks to it.

For the case, I used the metal case of two D2 SCSI jaz Drives, I constructed the two plastic front pannels, added braces to fix my PCB, modified the power supply, made the rear connectors, painted the cases in beige (and light purple for the eject buttons) and printed a sticker. Thus, I think that it's style corresponds to what it was done in the 80's, and especially for Hexbus products line.

 

hx5102m_3.jpg

hx5102m_4.jpg

hx5102m_1.jpg

 

hx5102m_2.jpg

Herie is a video of the PCB in action:

http://www.ti99.com/my_projects/HX5102M2.mp4

Amazing Fabrice, very nice work.

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The Apple Pie is an interesting card in the Apple world that interfaces between an Apple ][ and a Raspberry PI. The pie then emulates disks, serial, network, video - the works... it's basically a slave to the Apple ][ (and capable of being it's own machine as well). A PEB or sidecar that could interface with a PI would then benefit from all the hardware advances in the embedded Linux space. One such card in a PEB could replace every other card.

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I know the Apple Pie. I think that it can be useful for some users, but it is not for me... Absolutly not interested. My point of view about a such modern material is here: http://atariage.com/forums/topic/247983-is-it-a-ti-994a/page-2?do=findComment&comment=3636496

Edited by fabrice montupet

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@Hackmac, Ω and RickyDean : Thank you ! I'am happy that you apreciate my work :')

@Hackmac: I will detail my choices about the video board expension very soon here :-)

 

 

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I already have a pile of photographs from a Hexbus drive, courtesy of Jens-Eike Hartwig. I also have a dump of the "firmware" (ROM) on the drive. What would be particularly interesting are schematics for the drive; this would really be helpful for an emulation in MAME.

 

Anybody to follow the traces on the board? :)

Tonight, I sent to you the dump of my ROM Hexbus controller :-)

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Hello Fabrice,

 

many thanks for the ROM. I just verified with Jens-Eike's photos, there are two EPROMs 2564 (8Kx8), and this fact matches the dump that you delivered (only data from 0000-3FFF, remaining locations filled with FF). At first I got the wrong CRC value because I calculated the CRC over the whole 16K, but when there are two chips there is a CRC at the end of each one (i.e. at addresses 1FFE and 3FFE), and it verified correctly now. I attach a disk image with both ROMs - maybe we have some people here who are interested in disassembling them? To boldly go where ... ?

hexbus.dsk

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As far as I have got until now:

 

1. Good news: TI obviously did a lot of code recycling in the Hexbus floppy controller; many parts are taken from the original TI FDC for which we have commented listings from Thierry. That way, I was already able to identify the DSR operations, the subprograms, and some common subroutines. They even kept these typical "@>005A(R9)" (which calculated to 835A in the TI FDC), although there is no 8300 in the Hexbus floppy, but R9 has a different value. The lines are not identical, though, as there is no VRAM which the FDC made use of. There seems to be SRAM (4K) at E000-EFFF, the on-chip RAM (F000-F0F9, FFFA-FFFF), and the 16K ROM. There is a formatting routine inside the controller ROM that creates a floppy file system with some default settings. Interrupts are not used. A portion of the code must deal with the Hexbus interface; I have to find that still.

 

2. Bad news: The Hexbus floppy uses the Intel 8272A floppy controller, and yes, we have a 8271 controller in MAME. Pretty close, but not the same. I'll have to find out more about the differences, and I probably have to implement an emulation for the 8272A.

 

And TI again used that weird 16 sectors/track format instead of 18 sectors/track. I don't understand why you should give away 512 bytes per track. The MFM format offers by definition 50000 bits per track (250 kbit/s * 200 ms/track) , i.e. 6250 bytes, which offers more than enough space for 18*256 payload bytes.

Edited by mizapf
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That 16-sector per track thing seemed to be a bit fashionable back then for a lot of systems. Even the IBM PC could use the 320K format back then, IIRC (although it wasn't a default setting).

Edited by Ksarul

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