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Stuart last won the day on September 18 2016

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About Stuart

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  1. TMS is the prefix for their processors and support chips. TMS9900, TMS9995, TMS9901, TMS9902, ... TIM is the prefix for related chips that are also available as part of the standard 74LS logic family. TIM9904 = 74LS362, TIM9905 = 74LS151, ... TMP and TMX prefixes are also used for prototype and preproduction/validation(?) versions of the chips. Some processors also available as "SBP" versions, which use a different type of logic (I²L). SBP9900, SBP9989. TM990 is their range of microcomputer building block modules. http://www.stuartconner.me.uk/tm990/tm990.htm TI990 is their range of minicomputers. https://en.wikipedia.org/wiki/TI-990 Have never seen what TM/TMS actually stand for!
  2. No! Not unless you want a big bang, puffs of smoke, and possibly an extended visit to your favourite deity. The PEB transformer output to the power supply PCB is at most around 20 Vac. You can use different connections on the transformer for 110 or 240 Vac input, but the output voltage is far lower.
  3. Unfortunately the processor is still driving the address bus, and driving or reading the data bus, while waiting for GREADY.
  4. If you download the cartridge image now on my website and reprogram the cartridge, you should find it now resolves host names (let me know if not!). It calls a script on my website to do this using a hard-coded IP address, and that IP address changed a while ago ...
  5. I'll put the v9.2 files back up this evening - seems they got deleted from the server somehow. But I need to tweak a hard-coded IP address in them first. I'll confirm when they're good-to-go. Stuart
  6. The +5V goes through a few ferrite inductors between the power supply and pin 1. You might well find it works fine by connecting pin 1 direct to the power supply, but you might run into problems if you were to, for example, try to get the console through the FCC emission regulations again.
  7. My NanoPEB runs quite happily from a short +5V power cable I've run direct from the TI internal PSU board and out through the case by the expansion socket. So I still need to plug the NanoPEB in, but I don't need an external mains adaptor. My NanoPEB consumes about 80mA at +5V, and the console itself about 950mA.
  8. Shush! I was going to do that self-publishing stuff and sell him a hard copy for £50 ...
  9. Looks like ... https://archive.org/search.php?query=tms9900 ... is a useful page to bookmark.
  10. TMS 9900 Family System Development Manual (Application Report) (https://archive.org/details/bitsavers_tiTMS9900MstemDevelopmentManual1977_4482262/mode/2up). Contains many of the diagrams used in the "how-to-build-your-own-working-16-bit-microcomputer.pdf" book. 9900 Family Systems Design and Data Book. A hefty tome, but most of it covered in the other 9900 data books. TM 990/100M User's Guide (www.bitsavers.org\components\ti\TMS9900\tm990-100\1602000-9701_TM990_100M_Users_Guide_Dec78.pdf). This is a manual for a single board computer which contains full schematics and circuit descriptions. May be of interest. Hard copies for this or the /101 module come up on eBay occasionally.
  11. Presumably the chips used for the 8<>16 bit data bus multiplexer. Wouldn't be needed for the 8-bit external data bus 9985.
  12. Personally I'd start by replacing the two MCM6810 RAMs, but you need at least some level of soldering skills to do it.
  13. The 9918 outputs colour composite on a single pin. The 9928/29 outputs video on three pins - luminance (the 'black and white') on one, and colour difference on the other two - and these are combined into a single colour video signal in the (external) PAL UHF modulator. There are some links on the board that you set according to the VDP in use. So with a 9929 plugged into a board set up for a 9918, you're only getting the luminance signal, with no colour information.
  14. How about ... JNE JMP1 C @>0000, @>0002 'Set EQ to not equal. JMP JMP2 JMP1 C R0,R0 'Set EQ to equal. JMP2 ... Or ... XXX EQU >2000 STST R1 CZC @XXX,R1
  15. So you've set the switches such that you can write to the 8K RAM and read the same data back? Worth checking the supply voltage on pin 28 of the 48T08 when its plugged in and the computer's on. If it's less than ~4.75V then the device goes into write protect mode where you also can't read from it (but the normal 8K RAM would still work). The supply voltage is going to be less than the computer +5V supply anyway due to the diode in the battery backup circuit. If the voltage is low, might be worth just bending pin 28 out of the socket and connecting direct to +5V on the PCB and see if it then works.
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