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MicroSprite S100 board with TMS9918 and 4116 chips

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waltermixxx

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132
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Canada
I also have this posted in the Texas instruments section but thought it should be here as well, reallying looking for any information i can get my hands on, testing this board. :)

Hi there, I'm wondering what is the best way to test this board...
I have it installed on my "JAIR8080" which can be best discribed as a
Modern day Imsai based on Josh Bensadon's 8080 board, and Don Caprio's
Mini Front Panel. The serial ports are built in (8250 chips x 2) and so is an
sd card interface which acts as 4 drives for cpm.

The MicroSprite has two sets of Jumpers one for the Port address and the other for the interrupt.

I currently have the board set to use Ports 80 and 81.

when i power on the system, i do get a black raster on my lcd monitor on the video output,
so it looks like it's generating video. however right off the bat it's black. I was wondering,
if it should be black or if it should maybe have some random characters or something up on the display.

The RAM chips are a bit warm, but not hot, and so is the TMS9918. I'm sure I have 4116's somewhere i can try
replacing the ram with. But nothing currently has me thinking there may be an issue... Wondering about
the dreaded "black screen" Ti99/4a can get?

i dont have the schematic, and there appears to be no reference to it on the internet, except perhaps my own.

I have the VPD programming guide, and data sheets for the TMS9918, but wondering if I should be seeing anything
on the screen at power up or reset? is there a quick set of data i could send it to perhaps generate a red background,
and blue border?

I know i use the two ports to communicate with it, just confused somewhat on the best way to initialize it.

in MBASIC i can use OUT xxx, yyy ( Port number, Data )
I can also use A=INP(xxx) where xxx is the port number.


here are pictures of the board:

IMG_5155.jpg
IMG_5156.jpg
IMG_5157.jpg

I would love to be able to draw to this board...

:)
 
waltermixxx said:
I also have this posted in the Texas instruments section but thought it should be here as well, reallying looking for any information i can get my hands on, testing this board. :)

Hi there, I'm wondering what is the best way to test this board...
I have it installed on my "JAIR8080" which can be best discribed as a
Modern day Imsai based on Josh Bensadon's 8080 board, and Don Caprio's
Mini Front Panel. The serial ports are built in (8250 chips x 2) and so is an
sd card interface which acts as 4 drives for cpm.

The MicroSprite has two sets of Jumpers one for the Port address and the other for the interrupt.

I currently have the board set to use Ports 80 and 81.

when i power on the system, i do get a black raster on my lcd monitor on the video output,
so it looks like it's generating video. however right off the bat it's black. I was wondering,
if it should be black or if it should maybe have some random characters or something up on the display.

The RAM chips are a bit warm, but not hot, and so is the TMS9918. I'm sure I have 4116's somewhere i can try
replacing the ram with. But nothing currently has me thinking there may be an issue... Wondering about
the dreaded "black screen" Ti99/4a can get?

i dont have the schematic, and there appears to be no reference to it on the internet, except perhaps my own.

I have the VPD programming guide, and data sheets for the TMS9918, but wondering if I should be seeing anything
on the screen at power up or reset? is there a quick set of data i could send it to perhaps generate a red background,
and blue border?

I know i use the two ports to communicate with it, just confused somewhat on the best way to initialize it.

in MBASIC i can use OUT xxx, yyy ( Port number, Data )
I can also use A=INP(xxx) where xxx is the port number.


here are pictures of the board:

View attachment 32784
View attachment 32785
View attachment 32786

I would love to be able to draw to this board...

:)
Click to expand...


https://retrobrewcomputers.org/n8ve...860639/31624471/40516836/40516765/TMS9918.LST

The above example is set up for ports 0F8H & 0F9H, just change the board to match program or program to match board.

https://github.com/cbmeeks/TMS9918


TI refers to the 2 ports by the pin name mode.


Randy
 
Thank you that is a great start. :)

I will let you folks know how I make out... :)
I'm bringing my 8080 system to the VCF MW show
so hopefully I'll have something to show...


Thanks again for taking the time to respond. :)
 
Thanks for the Link, I was able to get the card to produce video by spoon feeding it what it needed into it's registers with a simple basic program that mimicked the z80 code.
It was quick and dirty and I just wanted to see if the card would produce video. I got help from Josh, we hooked it up to his scope, and determined there was black video being generated on start up. And we did get a random pattern of "stuff" on the screen after we spoon fed the registers. :)

I think this would actually be considered a rare, s100 video card, and by some accounts seems to be working fine. :) I pulled the TMS9918A and tested it in a Ti99/4a i have, and it worked, and i replaced the ram with some 4116 I had for a while that seem to work as well. Josh and I tested the MODE, CSW and CSR signals while running a little test program and they seemed to indicate the correct signals as well. :)

:)
 
waltermixxx said:
Thanks for the Link, I was able to get the card to produce video by spoon feeding it what it needed into it's registers with a simple basic program that mimicked the z80 code.
It was quick and dirty and I just wanted to see if the card would produce video. I got help from Josh, we hooked it up to his scope, and determined there was black video being generated on start up. And we did get a random pattern of "stuff" on the screen after we spoon fed the registers. :)

I think this would actually be considered a rare, s100 video card, and by some accounts seems to be working fine. :) I pulled the TMS9918A and tested it in a Ti99/4a i have, and it worked, and i replaced the ram with some 4116 I had for a while that seem to work as well. Josh and I tested the MODE, CSW and CSR signals while running a little test program and they seemed to indicate the correct signals as well. :)

:)
Click to expand...

Good news - and yes I assume it is rare. I remember it being advertised "back in the day".

I sometimes give my 2 cents worth and more often than not never hear back.


Randy
 
I started looking through byte and kilobaud magazines (online) for adds for it in 1983 ( the date on the board). Page by page, but I think using the "advertisers index" might be helpful as well. But I'm guessing there were no full page adds for it. But one never knows. I will update the thread if I find anything.
 
Here is some code i wrote ( With Josh's help ) that initializing the card in one of it's graphics modes.
basically it's just feeding into the registers the data required to initialize the TMS9918A chip. The data is first
written to the port, then the register in which the data is to go. The 7th bit must be 1 so its the register number +80H

So register 0 is 128
register 1 is 129 and so on...


5 PRINT "Initialising TMS9918A..."
10 READ A
20 IF A < 0 THEN END
30 OUT 81, A
40 GOTO 10
50 DATA 0,128
51 DATA 203,129
52 DATA 05,130
53 DATA 00,131
54 DATA 01,132
55 DATA 32,133
56 DATA 00,134
57 DATA 04,135
60 DATA -1
70 END


image3.jpg

image1 (7).jpg
 
I got the manual from Herb. Good quality scan, lots of information :).
and more importantly example programs in basic. :) I'll post some pictures and any programs
based on the examples in the manual. :) I don't suspect many folks have this card, so not sure to what end.
but either way, it is a very cool graphics card. :) and now I have some more information on it. :)

Thanks Randy and Herb :) I'm well on my way to becoming a MicroSprite Ninja :)
 
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