#A1000 Kickstart RAM ?
7 messages in this thread
I recently installed the KwikStart ROM bd in my A1000 and upgraded to WB
3.1. Everything works fine. Not long after that, I did the old 512K RAM
addition that was in V2 #1 of Amazing Computing. That went well. Since I'm on a
roll I'd like to know if it's possible to make the 256K of Kickstart RAM
available for general use in the system RAM pool. I seem to recall that there
is or was a program floating about that would do it. In fact, the KwikStart
documentation claims this. My question is: can this be done and where do I find
the program to do this ?
If there is no program to do this, does anyone know of a hack that would do
this ?
Thanx.
Regards, Owen Jones VE3YOJ
Owen,
as I recall, and this goes back a LONG way, you could use the program AddMem
to do the job. You'd need to know where the KS memory is located in order to
tell it to add it to the memory pool, but any one of the information programs
out there, such as SysInfo, should be able to tell you where it lives.
I could be wrong on this recollection, since it _has_ been a while.
Brian;
Thanx for the reply.
My concern is whether the ROMs and RAM occupy the same address space and
whether or not there's a way to remap the Kickstart memory away from this. On
the other hand, perhaps the boot code knows the difference between the ROM
space and the RAM space. If the later is the case then AddMem should work fine,
otherwise there may be a problem.
My Hardware Manual (WB 1.2) shows the system ROMs occupying a space from
0xF80000 to 0xFFFFFF – just 1/2 Meg. SysInfo shows the same thing but makes no
comment about Kickstart RAM space. This is consistent with the size of the 3.1
ROMs. The manual is mum about the Kickstart RAM space though. I suppose what's
really needed is a set of A1000 schematics.
Perhaps someone else will have some thoughts on this ?
Regards, Owen Jones VE3YOJ
Owen,
I seem to have missed a previous message but, the A1000's ROM was 256K
and only used to load the Kickstart image to RAM. Before giving my
A1000 to my brother ( hated to loose the signed case) I had added
the piggyback RAM chip hack in an old "Amazing Computing" article,
built a custom ROM board for the 2.01 ROM (runs OS2.04), and
manually hacked the kickstart RAM into another address space. Which
was added using the addmem command. Without changing the address
,in hardware of the kickstart RAM, Addmem won't work.
Of course this was many years ago, I use the A3000 now 🙂
James;
I don't suppose you remember how to do the Kickstart RAM hack, do you ?
That's all I really need to know in order to make use of an extra "free" 256K.
Otherwise my machine is substantially the same as your old A1000 (plus 1Meg of
Insider board).
Regards, Owen Jones VE3YOJ
Owen,
I was afraid you might ask:-) Unfortunately, I gave my brother the
instructions along with the computer and he is now in San Fransico. I
still have a copy of "Schematics and Expansion Specifiactions",
June 9, 1986 with a few notes but nothing that could be considered
instructions. There is a reference to Amazing Computing Vol 2 iss1 but
that may be the piggy backed RAM or the Kickstart RAM hack. As I recall I did
use an article for refence;-)
The jist was to modify the input/output of the DAUGCAUS and DAUGEN PALs
used to control the kickstart RAM. I recall there was article with specs
for to program modified PALs(PAL equations).
It is a moderate amout of work for 256K. Especially now:-)
I'll leave a note with my brother to see if he has unpacked, and can
find my instructions. I never thought anyone else would "try it at home".
If he can't find them I can give you info from my notes but… there is
no guarentee 1)It would work 2)The computer would work. RISKY!!!
James;
Sorry about the delay in responding – I've been off-line for awhile.
I'd have no problem with modifying hardware having been trained in
electonics. Regrettably, I lack the means to program PALs. I suppose I could
spend a few hundred dollars to pick up a programmer but, as you observed, it's
probably not worth it for 256K. In any case, I would not like to try it without
schematics and those are hard to come by. OTOH I would be curious to see what's
involved. If you should get the instructions from your brother and they don't
look too horrendous, could you email them to me?
Much obliged, Owen Jones VE3YOJ