Home »
Digital Archaeology »
Computer Arcana »
Apple »
Apple II »
Transwarp behaviour with ROMX
| Transwarp behaviour with ROMX [message #410669] |
Wed, 01 September 2021 02:02 |
|
|
Originally posted by: Andrew Roughan
The Transwarp manual says:
The only way to activate TransWarp is by powering-up, or "cold-booting",
the computer.
…
Accesses to the Apple's RAM and ROM are restricted to the Apple's clock
rate of
1 MHz; therefore, on power-up, TransWarp loads the Apple's ROM into its
RAM,
…
Writing a three (to $C074) will disable the TransWarp card completely and
pass processing control to the Apple's processor until the TransWarp is
again activated by cold-booting the system.
—-
This combination of behaviour makes coexistence with ROMX difficult.
Transwarp will shadow ROMX bank 0 at startup and then any attempt by ROMX
to change ROM is not actioned by TW.
If the TW is disabled to allow ROMX to function, can’t return to fast
speed.
Is there a way to force TW to update its ROM shadow copy?
E.g. Is there a way to force TW to think it has been cold booted without
also making ROMX think it has been cold booted?
Potentially a hardware switch.
Alternatively, can a new TW firmware help?
The firmware disassembly shows $1000 org which must be an internal address
space. There is no slot firmware visible when the TW is disabled.
Potentially a different firmware could be written to allow ROMX to do its
thing and then invoke shadow copy. Not sure if this is feasible.
Any other ideas?
Any input in the above?
Thanks
Andrew
|
|
|
|
Goto Forum:
Current Time: Fri Apr 19 04:23:38 EDT 2024
Total time taken to generate the page: 5.14774 seconds
Members
Search
Help
Register
Login
Home
