Notes on memory board for sale (v59)
Notes on memory board for sale (v59)
Memory board desc. being edited here. v59 and others.
68000 socket 8MB ram, A500/1000/2000/CDTV.
The www page for ram :
http://www.mkl211015.altervista.org/ram68k/
-- older cpld code versions have bugs -Cpld code can be changed with xilinx jtag programmer
-Options v58/V59 pcb cpld code for config out or in other boards have both
-config solution for cdtv (config after dmac)
-limit memory size under 8meg
-may not be compatible with accelerator processor boards - something to fix
Stacking of boards
-Under A500 keyboard is limited space
-so
separate boards that each have their own socket pins, e.g. ram and ide and cpu plugged in to a stack, is too high to fit in a500.
-space limited in cdtv
-stack of two boards should fit in a2000. a1000?
-A
soldered combination of ram(v59) and ide(v4xx), to same (separate type, not the very long strips on plastic black body) socket pins (with kapton insulation tape in between) will fit.
V59 can be plugged to top side of v4xx style ide boards, but it maybe tight with the polarising tab of idc cable connector or maybe not fit with boxed ide header (ide v402/v418). v401/419/420 have 1.27mm of extra clerance to ide connector.
About dram refresh:
To refresh, the cpld uses cas before ras refresh when 68000 address strobe(/AS) is negated.
Autoconfig(tm)
RAM autoconfig will work without wires in stock A500/1000/2000 that have no other autoconfig devices - except processor cards that hide their E8xxxx access. But the ram can be still incompatible until revised.
CDTV guide:
http://eab.abime.net/showthread.php?p=1233919
- other CDTV info
- config in/out, (I don't know if autoconfig usable. )EDIT: BOTH config in and OUT grounded on dmac.
-CDTV has DMAC chip that is autoconfig device
-80 pin diagnostic connector pins (is similar to a1000/500/2000 86-pin connector)
-DMAC chip pins 71,72. Grounded.
http://eab.abime.net/showthread.php?p=231369&styleid=4
http://www.l8r.net/technical/cdtv-technical.html
http://eab.abime.net/showthread.php?t=90281
A500 has config out contact grounded, this can be cut and replaced. Some of the side slot expansions can feed its config out back to a500 side slot contact?
Amiga 2000 has config in, out on zorro slots. Could make contacts with pcb material like vero board maybe? Config-in to ram board can be taken from last zorro slot (or pin 8 of u606 74ls32 chip.) leaving the slot otherwise unused.
In V4.4 the signal should be found also on a pcb via:
Amiga A2000 version 86-pin slot has config in but not config out? B2000 version should have both. Page 94 in A500 A2000 Technical reference manual