--NextPart_Webmail_9m3u9jl4l_983_1155515967_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit The bad news is you probably won't find 4044s, or you'll pay collectors' prices for them. The good news is that almost any modern static RAM could be adapted to the H8 bus if you don't insist of trying to make it fit in the WH8-16 card. It's a matter of making the address decoding work and buffering the address, data and control lines to the RAM -- and the schematic of the WH8-16 will show you how to do that. Most anything you could buy would be faster than needed (which is not harmful) and you'd probably wind up with one card that fully populates the H8's address space. Example: I found a 2K x 8 SRAM part with 250 ns access time at DigiKey for $4.28 (each). It's a 24-pin DIP (5V VCC) and appears at a cursory glance to be compatible with the requirements. An octal decoder and some buffers and eight of these chips would make a 16K memory board in probably half a card's worth of space. The chip cost would be under $50. See http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=81422&Row=148798&Site=US -------------- Original message -------------- From: WVerish@aol.com Dear Carroll: I have a 16 k static RAM memory board that came with my H-8, but it is un-populated. The chips required for it are TMS4044 chipsThey are 4096 by 1 bit. The computer currently has only 8K of static RAM installed. This makes it very hard to write any real BASIC programs due to the lack of string handling capability with only B.H. BASIC instead of extended B.H. BASIC. I know that my 16K board could probably work with other chips, but due to their cost I really can't afford to make a mistake. Any ideas? Thanks, Wayne --NextPart_Webmail_9m3u9jl4l_983_1155515967_0 Content-Type: text/html Content-Transfer-Encoding: 8bit
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From: WVerish@aol.com
Dear Carroll:I have a 16 k static RAM memory board that came with my H-8, but it is un-populated. The chips required for it are TMS4044 chipsThey are 4096 by 1 bit. The computer currently has only 8K of static RAM installed. This makes it very hard to write any real BASIC programs due to the lack of string handling capability with only B.H. BASIC instead of extended B.H. BASIC. I know that my 16K board could probably work with other chips, but due to their cost I really can't afford to make a mistake. Any ideas?Thanks,Wayne