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- The Amiga A1200: Inside & Out
- Part 2 Feb 10th 1993
- (C)1993 Silicon Synapse Electronics & John Kamchen
- SSE BBS (204)589-1078 MEGS of AmiTronics hacks.
-
- The information contained in this document should not be considered to be 100%
- accurate, as I am having a hard time finding anything official on this system.
-
- ---------
-
- After doing alot of phone calling, I was able to obtain the pinouts for
- both IDE drive formats (the 2.5" & 3.5"). These come from Maxtor, and are
- valid for both the A600 and A1200 (tho there is some debate as to whether the
- Maxtor 2.5" drives work reliably on the A1200). The pinouts are standard for
- any IDE drive, so the source doesn't matter much.
-
- The pinouts are as follows: (_NAME means signal active low)
-
- Name 2.5" 3.5" Desc
- _RESET | 1 | 1 | Drive reset
- GROUND | 2 | 2 |
- DD7 | 3 | 3 | Drive data bus bit 7
- DD8 | 4 | 4 | Drive data bus bit 8
- DD6 | 5 | 5 | Drive data bus bit 6
- DD9 | 6 | 6 | Drive data bus bit 9
- DD5 | 7 | 7 | Drive data bus bit 5
- DD10 | 8 | 8 | Drive data bus bit 10
- DD4 | 9 | 9 | Drive data bus bit 4
- DD11 | 10 | 10 | Drive data bus bit 11
- DD3 | 11 | 11 | Drive data bus bit 3
- DD12 | 12 | 12 | Drive data bus bit 12
- DD2 | 13 | 13 | Drive data bus bit 2
- DD13 | 14 | 14 | Drive data bus bit 13
- DD1 | 15 | 15 | Drive data bus bit 1
- DD14 | 16 | 16 | Drive data bus bit 14
- DD0 | 17 | 17 | Drive data bus bit 0
- DD15 | 18 | 18 | Drive data bus bit 15
- GROUND | 19 | 19 |
- key | 20 | 20 | Key for interface connector
- DMARQ | 21 | 21 | DMA request (not supported yet)
- GROUND | 22 | 22 |
- _DIOW | 23 | 23 | Drive I/O write
- GROUND | 24 | 24 |
- _DIOR | 25 | 25 | Drive I/O read
- GROUND | 26 | 26 |
- IORDY | 27 | 27 | I/O channel ready
- SPSYNC | 28 | 28 | Spindle sync (not supported yet)
- _DMACK | 29 | 29 | DMA acknowledge (not supported yet)
- GROUND | 30 | 30 |
- INTRQ | 31 | 31 | Drive interrupt
- _IOCS16 | 32 | 32 | Drive 16 bit I/O
- DA1 | 33 | 33 | Drive address bus bit 1
- _PDIAG | 34 | 34 | Passed diagnostics
- DA0 | 35 | 35 | Drive address bus bit 0
- DA2 | 36 | 36 | Drive address bus bit 2
- _CS1FX | 37 | 37 | Chip select 0
- _CS3FX | 38 | 38 | Chip select 1
- _DASP | 39 | 39 | Drive active/slave present
- GROUND | 40 | 40 |
- +5v | 41 | -- | +5v supply
- +5v | 42 | -- | +5v supply
- GROUND | 43 | -- |
- RESERVED| 44 | -- | Reserved for future definition
-
- As you can see, apart from the power pins, all the signals are exactly the
- same. The ones that say 'not supported yet' should still be connected.
- The 44pin connector isn't a normal .1" IDC header, it's more like .075".
- I'm still trying to track down the source of these connectors/cables. The
- local computer store should have some of these around, and I'll have to do 40
- solder joints to join it to a normal IDE plug. If I come up with a better
- way, I'll let you guys know.
-
- If you are like me, you will want to use a 3.5" hard drive on this system,
- because of the cost of those stupid 2.5" units (they run about $150 more than
- the equivalant sized 3.5" drive). Aside from the cost factor, there is a
- storage consideration. The largest 2.5" I've heard of is 120mb, but there
- might be a 240mb lurking around somewhere. Myself, I wouldn't put anything
- less that 240mb in this computer.
-
- * NOTE *
- The 3.5" drive you use must be an 'LPS' type (LOW PROFILE!).. 1 inch high
-
- -| There may be a conflict with your warranty sticker & a screwdriver |-
- When I bought my sysytem, the computer has something rattling around inside
- and the power LED didn't work.. plus something was wrong with the workbench
- screen. These were all valid warranty complaints, and I didn't do anything
- dishonest. The tech checked over the system (the mystery object fell out,
- the power LED worked, but the WB screen was still odd). I felt stupid, but
- went in with good intentions (the car always starts as the tow-truck
- arrives). Lucky me, they didn't put another sticker over a screw. You too
- may be just as lucky. But, if you take in your system with a 'phantom
- problem', you have to live with the results (such as paying the shop fee for
- wasting their time). As well, if you damage the computer (like cutting
- wires, bending metal, blowing the IDE chip) the warranty is for sure gone no
- matter what you offer as an excuse.
-
- Ever wonder why the drive is put in at an angle? It's not meant to look
- pretty (tho it does). The reason is simple: SPACE! The inside on the A1200
- is really cramped, what with all the metal shielding and all. In a 500, many
- people bolted the drive to the underside of the top case (under the vent
- holes) and it proved to work very well. The A1200 doesn't have that option.
- Space is at a premium.
-
- * DO NOT DAMAGE OR DISASSEMBLE ANY ORIGINAL CABLES OR CUT ANY METAL *
- * You should be able to restore the A1200 to as-new condition should *
- * it require warranty work in that vital first year *
-
- 1) Remove the floppy drive, make it external. This is as easy as it sounds.
- The floppy cable (34 conductor) can be extended by any means you see fit.
- Simplest way would be to buy a drive cable from the local computer store.
- The power connector for the floppy will be shared with the HD, so look at
- your needs, and come up with something. The HD is bound to have the
- normal 4 pin power plug. There will be some soldering done here, keep it
- neat. To shield the floppy cable, wrap it in aluminium foil & duct tape
- (run the power plug inside the shielding!). A case from Active or Radio
- shack can house DF0: (make it look nice, eh?). This is better than using
- a 'shuffle board' system, because it allows to keep the external drive
- port free for DF1-3:.
-
- Install the 3.5" HD in the floppy bay. Don't loose that angle bracket.
- The drive should sit really nice, and not be wedged against anything.
- One thing you have to look out for is that the drive connectors (40 pin &
- power) don't get wedged against the sheilding. You might need to bend the
- metal a wee bit, but I hope not.
-
- Doing it this way has two benefits: Simple to do (as easy as it gets) and
- should you need to take the machine into the shop for repairs, you can
- dismantle everything, put the floppy drive back in place, and close it up!
-
- You still need to get ahold of the Commodre Install disk to use the HD.
-
-
-