X-Andrew-WideReply: netnews.comp.sys.amiga.hardware X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Received: via nntpserv with nntp; Sat, 21 May 1994 15:39:12 -0400 (EDT) Path: andrew.cmu.edu!bb3.andrew.cmu.edu!news.sei.cmu.edu!toads.pgh.pa.us!godot.cc.duq.edu!news.duke.edu!convex!cs.utexas.edu!utnut!torn!uunet.ca!uunet.ca!geac!alias!imax!beltrix!ionews.io.org!nobody From: tsangc@io.org (Calum Tsang) Newsgroups: comp.sys.amiga.hardware Subject: A2090 FAQ (long) Date: 21 May 1994 01:46:58 -0000 Organization: Internex Online (io.org) Data: 416-363-4151 Voice: 416-363-8676 Lines: 367 Message-ID: <2rjp6i$5n2@ionews.io.org> NNTP-Posting-Host: nudge.io.org Notes for Commodore A2090A Hard Disk Controller ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Revision 4 Calum Tsang February 26, 1994 Sara's Place @ 416/626-0406 v42bis Toronto, Ontario Canada Email: tsangC@io.org / Calum_Tsang@comnet.cbmtor.gts.org About the Author ~~~~~~~~~~~~~~~ I've owned an A2000HD with A2090A for four years. I still like it. Please send any notes, bugs, problems and questions for me. Disclaimer ~~~~~~~~~ I write this because many people have acquired A2090A cards or lost their manuals and need information to run them. I am in no way associated with Commodore and also I do not take any responsibility for damages incurred by the information in this document. Thanks ~~~~~ Thanks to Steve Vetzal at Commodore Canada, Hai Dam and Nigel Maharaj, for information in this document. Contents: ~~~~~~~~ 1. How to Tell Which One You Have A2090/A2090A 2. Hardware a) Disabling Autoboot Functions b) All the Connectors, Around the World 3. Drives 4. A Note On A2000HD/A2500/20's With A2090A 5. Map O' Fun 6. How to Install an HD 7. The MountList 8. The Startup-Sequence 9. Special Info About Device Names 10.Reformatting for 2.0 11.Theory of Operation 1. How to Tell Which One You Have (A2090 or A2090A) ----> New <---- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ a. A2090-Non Autoboot HD Controller -Has words "A2500 HARD DISK CONTROLLER" printed on the board -Doesn't have three ROMs, for Autoboot on it. b. A2090A-Autobooting HD Controller -Has words "HARD DISK CONTROLLER" printed upside down on the top right corner of the board. -FCC ID: BR98YVA2090 / Assy. No. 311979 / Fab 311981 (mine) -Found on early model Amiga 2000HD/2500 -Often paired with Rodime RO3055B 44MB ST506 drives. -Has three ROMs, listed: (on my card) Board# Physical Size Revision Number ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ U50 HI Top centre, below J2 28 pin 315098-01 2090 AB5C U51 LO Top centre, below U50 28 pin 315097-01 2090 D32B U36 Top right 28 pin 390230-09 2090A 2FEF 2. Hardware ~~~~~~~~~~ The A2090 cards require an Amiga computer with Zorro II expansion bus-they were originally designed for the A2000, but they work equally well with A3000 and A4000 machines, according to Steve Vetzal. To autoboot with an A2090A, you'll need a Workbench AmigaDOS 1.3 ROM, or 2.x ROM. The A2090 series cards have two interfaces on board. An ST506 (IBM MFM type) interface and a SCSI (Macintosh type) interface allow one to use up to nine drives in a A2000. The A2090A revision has special autoboot ROM's that allow the hard disk to boot Workbench under 1.3 Kickstart ROM's on the motherboard. An interesting note: the A2090's have a Zilog Z80B CPU...more powerful that a Commodore 64! The A2090 and A2090A controller should be placed nearest the drive cage, so one can easily attach the hard disks. The LED Hard Disk light line from the front panel should attach to pin J5 at the rear end of the card, while the ST506 control cable (larger of two) should attach to connector J0. Each drive must have it's own data cable (smaller 20 pin flat) and these attach to J1 and J2 for the first and second drives respectively. The last drive in the two drive chain must be terminated-and the drive between the controller and the last one has to have the terminator packs removed. Not doing so will mean problems down the road. Connect the usual drive power into each unit as well. For SCSI, only one cable is needed, it attaches to either CN2 (50 pin flat) or CN1 (DB25 female on back panel). Usual SCSI termination is required. 2a) Disabling Autoboot ~~~~~~~~~~~~~~~~~~~~~ By placing a jumper on pins J4, you can disable the autoboot feature of the A2090A. This is required to work in a machine with another SCSI controller. The A2090A will fight with the controller with boot priority, unless it is disabled. 2b) All the Connectors, Around the World ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (these are all from my A2090A) Connector Location Size Function ----------------------------------------------------------------------- J0 Centre Middle 34 pin ST506 Control J1 Centre Middle 20 pin ST506 Data Drive 1 J2 Centre Middle 20 pin ST506 Data Drive 2 J4 Lower Right 2 pin Disable Autoboot J5 Lower Right 2 pin Disk Access Light, top positive CN1 Back Panel 25 pin SCSI DB25 Connector CN2 Center Right 50 pin SCSI 50 Connector 3. Drives ~~~~~~~~ You can use almost any kind of hard disk with the A2090. The older ST506 drives found commonly in IBM PC and XT clones can easily be attached. I've got the original A2000HD 44 MB Rodime RO3055B, as well as a Miniscribe 21 MB on my machine. You can also attach SCSI drives, swiped :) from old Macintoshes etc. You can't however, attach IDE, ESDI or SCSI-2 drives to it. For multiple drives, you'll need multihead cables. 4. A Note On A2000HD/A2500/20's With A2090A ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Workbench 1.3 A2000HD's have three partitions. DH0:, DH1: and FH1:. DH0: is an OFS (old file system) partition that has roughly 880K on it. DH1: has 3 MB and FH1: has the rest. The startup sequence on these machines ASSIGNs all the important directories to FH0: in boot, like C:, Utilities:, SYS:, Fonts: etc. It also copies a little icon to RAM: before LoadWB. This causes big problems with newer programs which like to install stuff onto the wrong drive. (see section on "reformatting for 2.0") 5. Map O' Fun ~~~~~~~~~~~~ Physical drives are attached to the controller, the A2090. Each physical drive, a unit, has a unit number-(see section on "Special Info About Device Names"). Keep this number in mind. Each physical drive has a RESx: partition-a two cylinder device you never see. They each also have a DHx: partition, a required OldFileSystem partition. Most people keep their DHx: partition small. However, I don't see wasting a cylinder on a DHx: partition, so I just reformatted my 21 MB Miniscribe to fill entirely with a DHx: partition. Speed isn't crucial, I have an unaccelerated machine. All other partitions can be in any FileSystem you choose. On my 44Mb Rodime, 40MB is a FastFileSystem partition. You can give them cute little names like Sara: and Matt: and others. But they have to be mounted manually or by startup-sequence. This is mainly why Commodore introduced the A2091 and the RigidDiskBlock automount features. This diagram is to explain the quirky nature of the A2090A's formatting. Relate to it, it might be a good example. Say you had a system like this: RES0 DH0 whatever partitions (one here) Unit 1, Rodime ST506: |--|---------|------------------------------------| RES2 DH2 whatever partitions (two here) Unit 3, Quantum SCSI: |--|--|------------------------|------------------| Notice even though you have a RES part and a DH part on unit 1, you still need them on unit 3? -All physical units (hard disks) require a two cylinder RESx: -All physical units must have a DHx: partition that is OFS -the x's in RESx: and DHx: are designated by the A2090 see the table below for 6. How to Install an HD ~~~~~~~~~~~~~~~~~~~~~~ (This is intended for the first hard disk, unit 1, ST506. For this drive, names would be RES0: for the weird two cylinder parition, DH0: for the first part. These numbers change for different units, like for unit 3, SCSI device 1, the names would be RES2: and DH2:) 1. Make a boot disk with Workbench on it. Copy Prep and HDInfo onto your C: directory on the floppy boot disk, along with MountList.HD into your devs: These utilities can be found on the A2000HD/A2500 ReInstall Disk, or on the A2090 Software disk. Unfortunately, they can't be distributed via electronic means. CBM may sell copies of this for a small fee though. 2. Edit the MountList.HD to your needs with the proper number of heads, Blocks per Track, Unit number etc, RES0: should always be Unit 0. (see section "The MountList") You will need to Prep, and Format and install all your system software on the first drive attached to your chain. You must have the RES0: or RESx: entry made in your MountList.HD for Prep to find it and create DH0: or DHx. One entry each for every drive you have. 3. Boot your machine with this floppy. Open a Shell. 3. Type: Mount RES0: from df0:devs/MountList.HD Prep RES0: 4. In Prep, either use a defined or your own spec HD. Answer the questions about it's capacity, and other drive info. When it asks for the High Cylinder or Last Cylinder of the first partition (DH0:), give it a number lower than the second partition you have listed in your MountList.HD. 5. Reboot with your boot floppy. 6. Drive DH0: should appear on your Workbench, but there should be nothing in it. Open a Shell, and type: Format DRIVE DH0: NAME BootPartition 7. The drive will format, and after, you can copy over your system software (just copy over your 1.3 Workbench disk), or run Install for 2.0. 8. After the initial preparation of the boot partition, every partition must be mounted and formatted with FORMAT. With the exception of the first partition on each physical drive, you can use FFS as well (add the FFS option on your command line). You also must modify your startup-sequence to mount these drives manually on boot up. 7. The MountList ~~~~~~~~~~~~~~~ The Mountlist, in your boot disk's DEVS: directory, will hold information about all drives that aren't automounted, like RESx: and DHx: for each physical drive. This way, the mount commands in your startup-sequence will reference the mountlist entries like this: mount fh1: from devs:mountlist (and for each partition you must do this) Here's a sample mountlist commented from the A2000HD reinstall disk: You'll need to modify it for your own drive(s). Remember: 1. Every drive needs a two cylinder RESn: partition entry 2. Anything other than the first partition (eg DH0:) needs an entry so you can mount it in startup) 3. Don't overlap cylinders! If your HighCyl on one part is 147, then your LowCyl on the next part must be 148! 4. The unit number can be found on the chart under "Special Info About Device Names" further in this file. /* This entry is present only as a reminder ... it is commented out. This part is not needed, since Prep asks for the first partition info. (Calum's Note: Why? cause Prep makes DH0: for you.) DH0: Device = hddisk.device Unit = 1 Flags = 0 Surfaces = 6 BlocksPerTrack = 17 Reserved = 2 LowCyl = 2 ; HighCyl = 20 Buffers = 17 BufMemType = 0 # */ FH0: Device = hddisk.device (hey kids, this is the second partition Unit = 1 entry. note how the entry is ended with Flags = 0 a "#" and how the low cylinder is one Surfaces = 6 number above the high or last cylinder BlocksPerTrack = 17 of the first partition as you typed into FileSystem = l:FastFileSystem the Prep program. You can name it SH0: Reserved = 2 or HAL: or CCR: or whatever.) LowCyl = 21 ; HighCyl = 71 Buffers = 50 GlobVec = -1 Mount = 1 DosType=0x444F5301 BufMemType = 0 # FH1: Device = hddisk.device Unit = 1 Flags = 0 Surfaces = 6 BlocksPerTrack = 17 FileSystem = l:FastFileSystem Reserved = 2 LowCyl = 72 ; HighCyl = 869 Buffers = 50 GlobVec = -1 Mount = 1 BufMemType = 0 DosType=0x444F5301 # RES0: Device = hddisk.device (This is important. Each drive requires Unit = 1 the first two cylinders for a special Flags = 0 section. RES0: is for the first drive. Surfaces = 6 This is so Prep can find the drive in BlocksPerTrack = 17 the beginning to actually prep.) Reserved = 2 LowCyl = 0 ; HighCyl = 1 Buffers = 1 BufMemType = 0 # 8. The Startup-Sequence ~~~~~~~~~~~~~~~~~~~~~~ As we said earlier, each partition that isn't DHx: needs to be mounted. That means any FFS partition too. Here's an example of how one must mount each drive in startup: mount Calum: from devs:mountlist.hd mount FH0: from devs:mountlist.hd mount Sara: from devs:mountlist.hd mount Matt: from devs:mountlist.hd mount SV0: from devs:mounstlist.hd The drive names represent entries for partitions in the mountlist. 9. Special Info About Device Names ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Some names MUST be used, their automatic, so don't use them in your extra partitions. Physical Device | 2 Cylinder Section | Unit | First Partition -----------------+--------------------+------+---------------- 1st ST506 Drive | RES0: | 1 | DH0: 2nd ST506 Drive | RES1: | 2 | DH1: 1st SCSI Drive | RES2: | 3 | DH2: 2nd SCSI Drive | RES3: | 4 | DH3: 3rd SCSI Drive | RES4: | 5 | DH4: 4th SCSI Drive | RES5: | 6 | DH5: xth SCSI Drive | RES(x+1): | (x+2)| DH(x+1): These are always the names and unit numbers. Prep will create them for you, based on what unit number you specify. 10. Reformatting for 2.0 ~~~~~~~~~~~~~~~~~~~~~~~ It's better to reformat DH0: into one big partition along with the space from FH0: if you have a 1.3 2000HD machine with a ST506 drive. Why? Because 2.0 Install won't check if you have enough space and will quit out on you! You can rerun Prep and give a new last cylinder for DH0:, and specify the last cylinder of FH0:. That will expand DH0: into the area occupied for FH0: and you'll get a large (4MB) systems partition. Of course being the first partition, it'll be slower because it's OFS. Run your Install as usual and remember to make sure your Startup-Sequence has the mount commands for your partitions. Also, 2.0 Install will copy everything into SYS:OLD. Copy out the Mountlist.HD into your new devs: and everything should be just fine. 11. Theory of Operation ~~~~~~~~~~~~~~~~~~~~~~ (note: this is all from observation) On power up, the A2090 checks each drive and waits for the floppy drives to check for boot sectors. This is because the floppy has boot priority over the HD. After that, it looks for a valid boot sector on the first drive (ST506). That first drive has a cylinder called RES0: and holds pertinent info for boot. Control is given to the boot partition DH0: (which is always reserved for the first partition on the first drive) and the machine boots off that partition. -------------- Questions and Extra Stuff 1. Under 2.0 OS ROM's, you don't need the first part OFS. FFS can be used. 2. Can you change the mask for RAM selection on the first partition? Prep doesn't seem to want to do it... 3. Will a 2090 really work in a 4000? Steve Vetzal of CBM says yes, but some net.folk say no. So far, I've heard one person say it won't. Any others? As always, questions, comments, ideas, dates are welcome :) Calum Tsang - Kami Jageman Productions - Commodore Amiga 3000/25 EMail: tsangC@io.org / Calum_Tsang@comnet.cbmtor.gts.org