ACA500 prototype 2 pictures and preliminary data
Prototype 2 of the ACA500 has passed three important tests:
1. MBRtest for all memory types
2. run a full AIBB module
3. girlfriend-installation-test (tm) passed without the need for a helping hand!
I might be able to gain a little speed on fastmem, but that will not change anything significant on performance. It's more like a "because I can" thing - if a refresh crosses an access, then the access loses up to three cycles, and that hurts feelings more than performance.
technical data up to this point:
- 68EC000 @ 14,3MHz (double speed of the A500)
- purely external connection, A500 doesn't have to be opened
- Computer will only be wider by just over an inch
- two CF-card slots: One for booting, and the other for exchanging data with a PC
- 2MByte physical RAM, where 1,5M are usable as fastmem and 512k are for Maprom
- trapdoor memory expansions (no matter what size) can still be used
- Chipmem-expansions can still be used
- ROM for things that I can't publish at this point
- local expansion port, will be documented openly (14MHz 16-Bit = twice Zorro-speed)
- clockport for A1200 hardware (Silversurfer, Catweasel MK2...)
- optional expansion with ACA1231/ACA1232
I'm still planning a steel cover for the thing, and there will be special versions for A2000 and A1000. Please note that the A2000 version will be incompatible with anything that does DMA - it won't work with GVP SCSI or A2090/A2091.