haxtor Posted December 10, 2012 Share Posted December 10, 2012 I purchaced a 32k x8 peb memory card today cheep with the intnet to mod it My plan: build an adapter to use the card as a sidecar or mod the card to be installed inside the main system. I have seen this done before with a disk card but never with a memory card. http://www.avjd51.dsl.pipex.com/ti/images/disk_system.jpg Has anyone attempted this before? Looking at the schematic, this shouldn't be too hard should it? http://www.mainbyte.com/ti99/schematic/mem_82_2.jpg Quote Link to comment Share on other sites More sharing options...
matthew180 Posted December 10, 2012 Share Posted December 10, 2012 (edited) It depends on your end goal. If you just want 32K in the console, I think a single modern memory chip with a simple programmable logic device (PAL or CPLD) would be the way to go. The use of a CPLD puts all the decoding and select logic into a single device, so you get a simple two-chip solution. However, if you want to keep the original "retro" look/feel of using original hardware, then hack away. The external nature of the first picture you linked looks like a failure waiting to happen with the memory card propped up and such. If you are going to keep the bulk of the original RAM card plus full-height floppy drives, IMO just keep things inside the PEB. Moving to a "side car" does not give you anything unless you end up with a configuration smaller than the PEB. Edited December 10, 2012 by matthew180 Quote Link to comment Share on other sites More sharing options...
+Vorticon Posted December 10, 2012 Share Posted December 10, 2012 I purchaced a 32k x8 peb memory card today cheep with the intnet to mod it My plan: build an adapter to use the card as a sidecar or mod the card to be installed inside the main system. I have seen this done before with a disk card but never with a memory card. http://www.avjd51.ds...disk_system.jpg Has anyone attempted this before? Looking at the schematic, this shouldn't be too hard should it? http://www.mainbyte....ic/mem_82_2.jpg Richard Bell sells internal 32K RAM kits that sit on the 16bit bus, and provide at least a 30% speed boost to the console. It's a little tricky to install because some chips have to be removed from the motherboard, but it's definitely feasible. He can be contacted at swim4home@facebook.com Quote Link to comment Share on other sites More sharing options...
Stuart Posted December 10, 2012 Share Posted December 10, 2012 (edited) It also easy to add 32K inside the console using two memory chips and 3 TTL chips - excellent instructions at http://www.mainbyte.com/ti99/16bit32k/32kconsole.html Edited December 10, 2012 by Stuart Quote Link to comment Share on other sites More sharing options...
haxtor Posted December 10, 2012 Author Share Posted December 10, 2012 Well for one issue, I don't own a peb yet. Another issue is that I cant find the schematic for that 32K 16 bit bus upgrade. I am really interested in learning how the various logic and bus chips work. Maybe I can work out a nice way to test out peb cards and do some experiments with them, I just need a little guidance in the right dirrection. I would have to say a goal I have is to be abble to use the peb ram card along with my speach sidecar. Quote Link to comment Share on other sites More sharing options...
+Vorticon Posted December 10, 2012 Share Posted December 10, 2012 One thing about hardwiring the expansion RAM to the motherboard is the fact that it will preclude using the SAMS card and some RAM disks. This is likely not an issue for haxtor since he does not own a PEB yet, but something to keep in mind nonetheless. Quote Link to comment Share on other sites More sharing options...
RXB Posted December 10, 2012 Share Posted December 10, 2012 SAMS is really the only way any advanced programming can happen on the TI99/4A as 32K is really so small to do much of anything. I work in GPL but that also requires a expanded memory of GRAM. Also RAMDISK is so much better then DISK for many reasons as an example is running a compiler is 6 times faster on a RAMDISK. 5 minutes vs 35 minutes for the same file to be compiled. A dream system is SAMS, (GRAM CARD) PGRAM, 32K (High speed version), RAMDISK, HARD DRIVE CARD and 80 Column card. When I had this set up there was really nothing my TI could not do much more quickly. Quote Link to comment Share on other sites More sharing options...
Tursi Posted December 10, 2012 Share Posted December 10, 2012 If you don't mind not getting the 16-bit boost, you can put 32k inside the console with only 2 ICs - the 32k SRAM and an AND gate. This will be far more reliable and draw far less power than trying to get the PEB card to work. The PEB card uses DRAM and has additional power requirements. My document on this mod is here: http://www.harmlesslion.com/text/TI%2032k%20Mod.pdf 1 Quote Link to comment Share on other sites More sharing options...
senior_falcon Posted December 11, 2012 Share Posted December 11, 2012 Another possibility is to do the so-called "matchbox" expansion. This worked fine, though like Tursi's, it doesn't get the speed increase of the more complex 16 bit expansion. It uses 4-8K static ram chips piggybacked and plugged into a socket. The socket has a bunch of wires which connect to the back of the cartridge port. I imagine that it could be done with a single 32K static ram chip. Here's more info: ftp://whtech.com/user%20groups/Brisbane%20Australia/TIBUG-1985-06.pdf Quote Link to comment Share on other sites More sharing options...
senior_falcon Posted December 11, 2012 Share Posted December 11, 2012 Oops - not enough detail in that last link. This one gives full instructions: ftp://kermit2.lizardhill.com/user%20groups/Lehigh/Lehigh8506.pdf Quote Link to comment Share on other sites More sharing options...
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