DISK DRIVES -101
2 messages · 2012-07-12 → 2012-08-13 · Yahoo Group era · View archive on archive.org
Participants: pxx1_2000_32724
Preserved from the Timex/Sinclair 2068 Yahoo Group (2001–2019), which is no longer online. Text reproduced from the archive.org archive; email addresses masked.
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1. DISK DRIVES -101
pxx1_2000_32724 · Thu, 12 Jul 2012 21:01
In case anyone else needs a refresher in Disk Drives-101,like myself, I thought I would share this info...Now I think I understand why I cant initialize a Drive (0) on my Larken.
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Thanks to David Solly, whom we should all know, and a user on Techmo.com named Zepper for the info.
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taken from...
OPERATING MANUAL
By Larry Kenny
Edited And Annotated By
David Solly
When using more than one drive, set the drive select jumpers on each drive as drive 0 to 3 respectively. Also, make sure that all terminator resistor packs are removed from the drives EXCEPT the drive that is connected closest to the end of the drive cable.
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If you did not purchase the disk drive cable, you can make you own using 2 feet of 34-conductor ribbon cable and 2 or more 34-position ribbon cable edge card connectors. The best way to attach the connectors to the cable is to use a vise to squeeze the connector. The connector on the interface end should be mounted opposite to the dive connector(s). If you use more than one drive, space the drive connectors 3 inches apart. Attaching the cable backwards will not cause any damage, but the drives will turn on.
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Below is by ZEPPER - December 16th, 2008 - techimo.com forum member
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If your 5.25" floppy actually has edge card connectors, then it isn't the last generation as the last had the pin type connectors just like the 3.5" FDDs. Anyway, jumper settings on the drive are important. The only ones that should need to be set are the drive select jumpers and termination, if available. Generally if your cable has a twist in it between the end and middle drive connectors, then the DS jumpers should be set to 1 (actually stands for the second drive and 0 is for the first drive - the twist does the choosing sort of like CS, cable select, for PATA HDDs) for both drives (this was to simplify system assembly for assembly-line drones as they wouldn't have to set jumpers on the FDDs - some drives have switches instead of jumpers). If your floppy cable has no twist (common in the early days), then your drive needs to be set properly to DS-0 for the first drive and DS-1 for the second drive and you put the first drive on the end of the cable so it would be properly terminated (enable the drive termination also if available). Generally the cables had a color stripe on one edge and that is supposed to be the "pin-1" edge which should go to pin one on the mobo and the no. 1 pins on the drive connectors. Here's a pic of the current standard floppy cable with the "cable select" twist: http://www.cablesdirect.com/prodimages/CC2205B_LR.jpg
and on this page is one with both 5.25 and 3.5 FDD connectors: Floppy Cables it also has the twist. Some FDDs have drive select jumpers that read D1, D2, D3, D4 (that is the "human" way), while more likely is the D0, D1, D2, D3 (the technical order of numbering) where you set D0 for physical drive one and D1 for physical drive 2 when the drives are on untwisted cables.
. Early 5.25" drives came from the factory preset for DO/D1 while later drives came preset for D1/D2 for the twist cables depending on the marking standards for the drive. This, once again, is the key: for twist cables, ALL drives are set to the second drive which could be marked D1 or D2 depending on the marking standard used on the drive and the position on the cable chooses which is Master and which is Slave. While on the old, non-twist, cables, the jumper on the drive chooses which is Master and which is Slave. In both cases, it is conventional to put the Master drive at the end of the cable - it is forced on the twist cable, and optional on the flat cable. 5.25 and 8" Floppy drives also may have terminator resistor packs which may be plugged into a dip socket to enable termination or removed from the socket for disabled or enabled/disabled by jumper or switch. Your drive mfr site should have info on your particular drive (in the "archive" section as these haven't been produced for years). Generally only the drive on the end of the cable needs or should have the terminator enabled (if it's available for changing) to prevent signal reflection (aka ringing) in the cable. Later drives had "balanced termination" and had no way to enable or disable it.
...........Some jumper blocks have a reason to have a cross-linked jumper but most often it's just a convenient way to park a spare jumper connected across two ground pins (all the pins in one row are almost always ground and all the signal pins are in the other row this makes every other wire in the cable a ground which provides a level of shielding for ribbon cables).
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STILL NO WORD ON FORMATTING THE 3INCH HITACHI DRIVE WITH LARKEN...IE#OF TRACKS OR SETTING IT UP AS DRIVE (0).
2. Re: DISK DRIVES -101
pxx1_2000_32724 · Mon, 13 Aug 2012 16:06
Switches Select Options
There are eight DIP switches located on the upper right-rear panel of the AMDC. These allow the following configurations:
Switches 1 through 4 are density selection switches that allow you to configure the drives for either single or double density on boot-up. The density of the boot drive is determined by the disk installed at boot-up. These switches have no effect if the controller is set for DOS 3.0.
Switches 5 and 6 determine which drive will be the boot drive. The factory setting is for drive 1, but any drive up to and including 4 may be selected for this function.
Switch 7 is used when more than three drives are connected to the controller, and is particularly useful when there is a 5¼-inch drive attached. When this switch is on, the external drive will be recognized as drive 1. When it is off, the 3-inch drives are 1 and 2, and the external drive is drive 3.
Switch 8 sets drives that have been selected as dual density to 256 bytes per sector when off. When switch 8 is on, it sets all drives to be Atari 1050 compatible for use with DOS 3.0. When switch 1 is on, disks with 256 bytes per sector will not be recognized.
The 3-inch drives are also available as a dual drive without a controller. This version is called the AMDISK IIIB and is fully compatible with the AMDC-1 or 2. The AMDISK IIIB in conjunction with an AMDC-2 lets you have a total of four double-density drives that take up about the same desk space as one Atari disk drive.
If you have 5¼-inch dual-density disk drives with controllers that use the industry standard 34-pin ribbon cable for drive connection, you can use the AMDISK IIIB as add-on drives.
...I knew I would find the answer sooner or later....thanks for all the help!