Hello,
This morning I was sitting in the train (from leeuwarden to harlingen) and I
was thinking........
The dude the wrote the novaxis scsi probably used an INIR for retrieving
data from the SCSI interface a
faster way to do this is use a lot of INI's..... But how can I alter this? This stupid thing
is in ROM.
The solution to this problem is simple... copy the rom to ram... To a
secondary mapper in page 2... alter the code and reset the computer(software
reset) and de BIOS will install the Novaxis RAM... I still have to search
for the graph key check in the code so you can disable the Novaxis-ROM and
not the Novaxis-RAM(It's suddenly looks like if you have two
NOVAXIS-interfaces in your computer if you don't dissable one of them).
Anyway.. This is the original code in the rom..
LD B,#40
INIR
JR FB
I replaced it with the following code.
CALL #4220
JP #5299
#4220 ( on this address (in the rom) the basic call strings are stored,
just overwrite it)
Put 64 INI's on this address and a ret ofcourse.
Here are some HDD speed checks I measured on the following system:
7MHz MSX2+ with a Qantum fireball HDD.
EI DI
Normal Code: 262 275 KB/S
Altered Code: 315 341 KB/S
* Values meaured with DOSSCAN.
I will make a driver for this so you simple run the program and it will do
the rest.
There is a lot to improve in this rom.... The man used a lot of JR's instead
of JP (If no jump is made then JP is faster)
Greetings Marcel Delorme
This morning I was sitting in the train (from leeuwarden to harlingen) and I
was thinking........
The dude the wrote the novaxis scsi probably used an INIR for retrieving
data from the SCSI interface a
faster way to do this is use a lot of INI's..... But how can I alter this? This stupid thing
is in ROM.
The solution to this problem is simple... copy the rom to ram... To a
secondary mapper in page 2... alter the code and reset the computer(software
reset) and de BIOS will install the Novaxis RAM... I still have to search
for the graph key check in the code so you can disable the Novaxis-ROM and
not the Novaxis-RAM(It's suddenly looks like if you have two
NOVAXIS-interfaces in your computer if you don't dissable one of them).
Anyway.. This is the original code in the rom..
LD B,#40
INIR
JR FB
I replaced it with the following code.
CALL #4220
JP #5299
#4220 ( on this address (in the rom) the basic call strings are stored,
just overwrite it)
Put 64 INI's on this address and a ret ofcourse.
Here are some HDD speed checks I measured on the following system:
7MHz MSX2+ with a Qantum fireball HDD.
EI DI
Normal Code: 262 275 KB/S
Altered Code: 315 341 KB/S
* Values meaured with DOSSCAN.
I will make a driver for this so you simple run the program and it will do
the rest.
There is a lot to improve in this rom.... The man used a lot of JR's instead
of JP (If no jump is made then JP is faster)
Greetings Marcel Delorme
