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CompuPro - ECONOROM 2708
This was Godbout's second EPROM board following on from the original ECONOROM (which only took 5204 EPROMS).

CompuPro EconoROM 2708

This board provided space for up to 16 2708s, one of the most popular high density EPROMS at the time. EPROMS give the advantage of retaining stored data when power is removed.  EPROMS are erasable; that is, after programming they may be erased and reprogrammed with other material. The EPROM locations on this board are grouped in four independent 4K blocks. The on-board DIP switch (no jumpers required) provided addressing on any 4K boundary Additionally, each 4K block contains an independent disable switch. This board also featured a wait state selection switch to select zero or one wait state, provision for use of PHANTOM input (line 67), a switch addressed power-on-jump feature, thorough capacitor bypassing of supply lines to Suppress noise transients, plus on-board regulation and heat-sinking for reliably cool operation.

One problem with the board is there is no Phantom OUTPUT line. So the onboard ROMS cannot overlap with S-100 Bus RAM in the same memory space -- a serious limitation.  Most ROM boards like this pulled the Phantom line low if addressed thereby inactivating any RAM board in that same address space and thereby avoiding a bus conflict.  If you use 8K,16K or 32K RAM S-100 boards you may be OK, if you configure them correctly. Not so for the later 64K RAM boards.
The manual for this board can be obtained here


Other CompuPro S-100 Boards
CPU8085-88  CPU86-87  CPU-Z  Disk1  Disk1A  Disk1B  Disk2  Disk3   EconoROM2708  Interfacer 1  
RAM Boards   Interfacer 3  Interfacer 4   Interfacer II   M-Drive  MPX-Board  PC-Video  
System-Support1  System-Support2   SPIO  Spectrum  SP186   CPU-286
   68000  32016  SPUZ


This page was last modified on 11/30/2013