Chefgon Posted April 10, 2019 Share Posted April 10, 2019 I'm assembling my first TI-99 system and I was hoping to use an original Texas Instruments Memory Expansion sidecar but I'm not sure how rare they are. How often do these show up for sale? Should I give up now and buy a modern alternative or keep checking until one shows up on the market? Quote Link to comment Share on other sites More sharing options...
+save2600 Posted April 10, 2019 Share Posted April 10, 2019 Give up now and buy one of the modern solutions. 2 Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted April 10, 2019 Share Posted April 10, 2019 Personally I'd give up now. Why? 1) They take up a lot of desk space and are usually a little banged up looking. 2) They are old, so chances are higher that they will stop working sooner than new tech. 3) The price you'll pay for an old one is probably higher than a new one. 4) If you want to expand later (like with a TIPI), you'll have to get a new one anyway. So... why waste your money on an old one? Keep your future expansion options open, buy the Jedimatt42 version from arcade shopper << BY CLICKING HERE >> and save the time and the hassle of trying to find an old clunky beater. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted April 10, 2019 Share Posted April 10, 2019 These don't come up often, it would depend on how authentic you want to stay. Quote Link to comment Share on other sites More sharing options...
twoodland Posted April 10, 2019 Share Posted April 10, 2019 An option would be to get a PEB. That way you keep the stock look and have modern options installed as well such as the TIPI and SAMS boards. It may be that it ends up not being that much more than an original sidecar. 1 Quote Link to comment Share on other sites More sharing options...
Chefgon Posted April 10, 2019 Author Share Posted April 10, 2019 (edited) Okay, follow-up question. I already have a Disk Controller sidecar, will Jedimatt's memory expansion work with that? Can it be added after the disk controller in the chain, or can its TIPI expansion interface be converted to a standard pass-through port? For clarity, I currently have no intention of using a TIPI. Outside of maybe a Lotharek my intent is to keep the system as original as possible. Edited April 10, 2019 by Chefgon Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted April 10, 2019 Share Posted April 10, 2019 I don't know if it passes power down the chain, but if not, I think it'll still work at the end if you power the 32K separately. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted April 10, 2019 Share Posted April 10, 2019 Okay, follow-up question. I already have a Disk Controller sidecar, will Jedimatt's memory expansion work with that? Can it be added after the disk controller in the chain, or can its TIPI expansion interface be converted to a standard pass-through port? For clarity, I currently have no intention of using a TIPI. Outside of maybe a Lotharek my intent is to keep the system as original as possible. I don't believe the DC passes it down, I think it has to be last in the chain, but I could be wrong. Quote Link to comment Share on other sites More sharing options...
Chefgon Posted April 10, 2019 Author Share Posted April 10, 2019 (edited) I don't believe the DC passes it down, I think it has to be last in the chain, but I could be wrong. I've heard that the Disk Controller has to be last in the chain, but I find it odd that it has a pass-through port on the side if nothing will work in it. But then I've also heard that the 32k has to be first in the chain (or second after the speech synthesizer) so it seems there are multiple possible rules working against me. If both of those rules are power-related, maybe the external power supply with Jedimatt's device would solve the problem and let me put it after the Disk Controller? I don't understand the nature of these rules well enough to know about workarounds. Edited April 10, 2019 by Chefgon Quote Link to comment Share on other sites More sharing options...
Casey Posted April 10, 2019 Share Posted April 10, 2019 A complete TI sidecar expansion required the Speech Synthesizer first, the 32K memory expansion unit second, and then the rest of the devices can be in any order (according to the manuals). Originally, only 3 devices in series were supported, but something in the 32K unit allowed for 3 units to be placed in series after it, increasing the amount of devices that could be connected. 1 Quote Link to comment Share on other sites More sharing options...
HOME AUTOMATION Posted April 10, 2019 Share Posted April 10, 2019 Okay, follow-up question. I already have a Disk Controller sidecar, will Jedimatt's memory expansion work with that? Can it be added after the disk controller in the chain, or can its TIPI expansion interface be converted to a standard pass-through port? For clarity, I currently have no intention of using a TIPI. Outside of maybe a Lotharek my intent is to keep the system as original as possible. The connectors are physically incompatible. 1 Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted April 10, 2019 Share Posted April 10, 2019 the 32k side car has a PIN connection to the right of it, so it will have to go on the end.. I have one set up here with a speech then tirs232 sidecar, 32k then tipi all works fine 2 Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted April 10, 2019 Share Posted April 10, 2019 On the original sidecars, the final spec actually allowed up to six devices. TI manufactured five different sidecars, and when you put the Thermal Printer onto the train, that made six. . . 2 Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted April 11, 2019 Share Posted April 11, 2019 Probably bus buffers. I haven't seen a TI 32K sidecar, but I bet it has some 74'244 and 74'245 chips before the right hand port. Anyway, that's just a guess. -M@ 1 Quote Link to comment Share on other sites More sharing options...
Chefgon Posted April 22, 2019 Author Share Posted April 22, 2019 (edited) Hey guys, Sorry to bump an old thread, I just wanted to record for posterity that the modern 32k sidecar DOES work as the third car in the chain (after a Disk Controller) with an external power supply. Thanks for the help, everyone! Edited April 22, 2019 by Chefgon 5 Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted April 22, 2019 Share Posted April 22, 2019 OH! That sidecar... I thought you meant the TI model... -M@ 1 Quote Link to comment Share on other sites More sharing options...
iliketurtles Posted July 4, 2019 Share Posted July 4, 2019 (edited) On 4/10/2019 at 1:51 PM, Chefgon said: I've heard that the Disk Controller has to be last in the chain, but I find it odd that it has a pass-through port on the side if nothing will work in it. That pass-through port on the side of the Disk Controller is for the Thermal Printer, IIRC. Edited July 4, 2019 by iliketurtles Quote Link to comment Share on other sites More sharing options...
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