Only for complementation of Nestor's MegaSCSI Info...
I made a simple translation from the original manual of MegaSCSI.
But I don't know if it works.
My comments is between "[" and "]", Ok?
=================================================================
Direct Acess Function
Before use a Direct Acess Function you must do a "SPC register bank
mapping" [really I don't know what its mean yet] othewise it may not
work.
--------------------------------------------------------------------------------
BUS RESET (Function #C1)
Input : none
Output: none
Descr.: Do a SCSI BUS RESET and Initialize SPC.
--------------------------------------------------------------------------------
SELECTION (function #C8)
Input : C=SCSI target (#01,#02,#04,#08,#10,#20,#40,#80)
Output: Cy=1 if error
A = error code if Cy=1
A = Next bus phase if Cy=0
Descr.: On bus SCSI execute a "Arbitration-Selection phase".
During use of SCSI bus, in case of a lost arbitration a
"arbitration error" (error code 12) is returned, in case of a try
execute a Target Selection and get a Selection Timeout a "Not ready"
(error code 2) is returned.
In case of Selection phase terminate without errors, A register return
the next bus phase to be done. It is equal to SPC's PSNS register.
BIT SIGNAL
bit7 REQ (request)
bit6 ACK (acknowledge)
bit5 ATN (attention)
bit4 SEL (select)
bit3 BSY (busy)
bit2 MSG (message)
bit1 C/D (control/data)
bit0 I/O (input/output)
A.3-0 PHASE
0xxx Bus free
1000 Data out
1001 Data in
1010 Command
1011 Status
1110 Message out
1111 Message in
--------------------------------------------------------------------------------
DISCONNECT (function #C9)
Input : none
Output: none
Descr.: Wait Target to set free the SCSI bus.
On SCSI bus, after all transation terminated ever execute a
DISCONNECT.
--------------------------------------------------------------------------------
SET ATTENTION (function #CA)
Input : none
Output: none
Descr.: Make "asaato" [this is a english word written with katakana, but
I can't identifie the original word, Soriano, do you know this word?] of
SCSI bus ATN.
When after SET ATTENTION executing SELECTION (function #C8) and
SELECTION is teminated with sucess, the SCSI bus change to "message out"
phase.
--------------------------------------------------------------------------------
RESET ATTENTION (function #CB)
Input : none
Output: none
Descr.: Make "negeeto" [this is a english word written with katakana,
but I can't identifie the original word] of SCSI bus ATN.
After execute SET ATTENTION (function #CA) when has no necessity
of this, ever execute a RESET ATTENTION.
--------------------------------------------------------------------------------
MANUAL TRANSFERRING (function #CC)
Input : BC = number of bytes to be transferred (0 mean 65536)
D.2-0 = bus phase
HL = transfer data adress
Output: A = next bus phase
BC = number of byte that cannot be transferred.
Descr.: On SCSI bus, execute a tranfer phase.
"deeta tensou houkou wa jikkou-suru BUS PHASE ni yotte
jidou-teki ni kettei-saremasu." [I'm unable to translate it in anyway,
if any one know what its mean....]
Is not possible to put data in page 1.
--------------------------------------------------------------------------------
HARDWARE TRANSFERRING (function #CD)
Input : BC =bytes per sector
E = number of sectors to be transferred (0 mean 256)
D.2-0 = bus phase
HL = transfer data adress
Output: Cy=1 if error
A = error code if Cy=1
A = next bus phase if Cy=0
E = number of sectors that cannot be transferred.
Descr.: "deeta tensou houkou wa jikkou-suru BUS PHASE ni yotte
jidou-teki ni kettei-saremasu."
Is not possible to put data in page 1.
In hard transfer mode, due to transfer data timming check is not
executed and due to other things [which I didn't understood], It can
transfer data faster than Manual transferring (function #CC).
During data tranferring, if a parity error occurs in SCSI bus, a "Data
transfer error" (error code 4) is returned.
================================================================================
DSKIO (#4010)
Input : Cy=0 read
Cy=1 write
C.7=0 ?
C.7=1 ?
A=DOS partition number (0-7)
B=number of sectors (0 mean 256)
C=media ID if C.7=1
C.6-0=first sector number (bit22-bit16 if C.7=0)
DE=first sector number (bit15-bit0)
HL=transfer data adress
Output: Cy=1 if error
A = error code if Cy=1
B = number of sector that was not read.
================================================================================
================================================================================
I don't understand japanese very well and I don't english very well too
(I speak Portuguese), but I made my best to translate some parts of
MegaSCSI's japanese manual losting half of my weekend. Unfortunately I
can't guarantee that this translation is 100% free of error. I hope
giving this first step anyone which know japanese better than me make a
correction of this text and write a more detailed document.
Best Regards
Alex Mitsio Sato
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