By Bob Applegate
Adding I/O devices that don’t need much address space. On the KIM-1, the space from 1400-17FF is grouped into the K0 block but only 17xx are used, leaving 1400-16FF open for use. To decode that range into four blocks of 256 bytes is easy using a single chip and a few signals from the KIM Clone expansion bus:
Everyone has a 74LS138 in their parts collection, so just connect a few signals from the expansion bus and use one of the three signals from the 138 to decode which block you want to use. Use the A0-A7 address lines to decode into smaller pieces.
See also:
RSC-Forth
This page is about the operation and use of the Rockwell Single-Chip RSC-FORTH system as implemented in the Rockwell R65...
This page is about the operation and use of the Rockwell Single-Chip RSC-FORTH system as implemented in the Rockwell R65...
RSC-Forth R56F11 R6501Q
Rockwell made many 6502 variants. Some were 'SOCs', complete computers in an IC. and Rockwell was strong in Forth, e.g....
Rockwell made many 6502 variants. Some were 'SOCs', complete computers in an IC. and Rockwell was strong in Forth, e.g....
R6501Q kit
I have two R6501 IC's. One came with the Glitchworks GW-R65X1QSBC-1 kit, a R6501Q. The other from ebay, a R6501AQ (A for...
I have two R6501 IC's. One came with the Glitchworks GW-R65X1QSBC-1 kit, a R6501Q. The other from ebay, a R6501AQ (A for...
R65F11 Forth computer
I have recently acquired a R65F11 IC. This IC is part of the RSC (Rockwell Single Computer) Forth system. Rockwell Sin...
I have recently acquired a R65F11 IC. This IC is part of the RSC (Rockwell Single Computer) Forth system. Rockwell Sin...