Confusion over 800k external floppy drives. Also: CapNet

[Gorgonops]

I've done quite a bit of Googling and I *think* I've figured the situation out, maybe, but perhaps someone here could help me confirm if I've got it right.

My recently acquired Fat Mac (512k, no 'e') has the normal 400k drive internally, and also came with an 800k external drive. Said drive is a model M0131, the one with no eject button or passthrough connector. The drive seems to work fine when the machine is booted from a System 3.2/Finder 5.3/HD-20 init disk in the internal drive, but I found that the Mac won't boot from the external drive (I remember thinking that Macs were supposedly bootable from either drive), and in fact I've gotten a couple "Sad Macs" that seem to be associated with having a disk in the drive at all at boot time. The machine only came with the System disk so until yesterday that's all I knew. Now I have MacWrite and MacPaint, generated on a Plus via DiskCopy 4.2. Said floppies have System 2.0, Finder 4.1 on them and boot the 512k on the internal drive, but the external drive doesn't appear to work properly. (If I insert a disk I get a "System Error" crash.)

Further digging suggests that in order for that model 800k drive to work *requires* the HD-20 init be present on the system disk booted in the internal drive and that this mechanism isn't bootable on the 512k. Is that indeed true? (Wikipedia's article about Apple floppy drives states with regard to the later "A9M0106" model: "But, unlike the Macintosh 800K External Drive, the Apple 3.5" Drive can be used natively with the 64K ROM stock Macintosh 128K & 512K without the HD20 INIT, but only with 400K MFS formatted disks.") If so that's sort of a bummer. Can someone confirm that the later model drive actually works seamlessly as a 400k drive with a 128k or 512k? (Or, conversely, that the problems I'm seeing aren't unique to something wrong with my system?) I might need to add the later model drive to my mental swap meet shopping list.

On the flip side I could always mostly work around the problem by just transferring software to the later version System disk I guess, but the "HD-20 Startup" disk I have only has a few K free on it. (IE, it has less space free on it than a 2.0/4.1 floppy *with MacPaint or MacWrite* on it.) I haven't had the chance to experiment yet, but is it possible to:

A: Copy the "System" folder to formatted 800k disk

B: Copy the desired application(s) to said disk

C: Boot from the HD-20 startup, insert the 800k disk in the external drive, and then remove the HD-20 startup so I can use a 400k data disk?

(And D: Are there things I can strip out of a 3.2/5.3 System folder to make it smaller?)

Also relating to the 512k: I finally got my Ethernet->Localtalk bridge bridging with the Mac Plus. Of course that has me itching to see if the 512k can join the Netatalk fun. I have a 9 pin to 3 pin "Localtalk Wiring" dongle for the 512k, but the Ethernet bridge and the dongle for the Plus is PhoneNet. I've tried looking up a schematic for DIY-ing a PhoneNet connector and the few leads always redirect to a schematic for "CapNet". By any chance has anyone here actually cooked up a "CapNet" connector and successfully used it on a network mixed with commercial PhoneNet devices with any success? (Or is there a simple way to connect the existing LocalTalk dongle I have to the Phonenet segment? I've seen hints that adapters for that existed.)

Mucho thanks, and sorry for being such a noob when it comes to this truly ancient hardware.

 

[NJRoadfan]

When I had a 512K, the Apple 3.5" drive off my Apple IIgs worked fine for booting and use. With the HD20 INIT, it had no problem working with 800k HFS disks. As for Localtalk connectors, I found DE-9 phonenet ones on ebay for pretty cheap since I needed one for the Fastpath 4.

 

[bbraun]

My M0131 does not boot my 64k ROM 512k either.

I haven't made one of those CapNet things, but I'd be interested in hearing about any experiments with building one. The DE9 versions of the phone net adapters are slightly more difficult to find, and more expensive than the minidin8 ones. Just of the top of my head, adapting the minidin8 to DE9 should be entirely passive, since it should be the same signals.

 

[Gorgonops]

The DE9 versions of the phone net adapters are slightly more difficult to find, and more expensive than the minidin8 ones. Just of the top of my head, adapting the minidin8 to DE9 should be entirely passive, since it should be the same signals.

Yeah, there's one on eBay for $13, while you can have three of the DIN-8 ones for $7. Does anyone know a part number for the 8 pin Mini-Din socket? Unless I can get another spare I'd probably rather make an adapter cable than the more obvious expedient of cutting the cable off the transceiver.

I was thinking I should have most of the parts I'd need for the CapNet thing out in the garage, but I'm sort of nervous about being the first one to try mixing it with commercial Phonenet dongles for obvious reasons. (Although it sounds like the RS-422 drivers in the Mac *should* be pretty tolerant of even hard shorts I don't really want to test just how tolerant, particularly after 30 years.)

 

[mcdermd]

I have four A9M0106 drives. Would you like one?

 

[NJRoadfan]

Yeah, there's one on eBay for $13, while you can have three of the DIN-8 ones for $7. Does anyone know a part number for the 8 pin Mini-Din socket? Unless I can get another spare I'd probably rather make an adapter cable than the more obvious expedient of cutting the cable off the transceiver.

8 pin Mini-DIN jacks should be available from just about anywhere.... being a DIN standard. Digikey stocks several types.

 

[Paralel]

If you want to sell the M0131, if it's a platinum model, I'll buy it off of you.

 

[Gorgonops]

I have four A9M0106 drives. Would you like one?

Considering an outstanding threat someone has hanging over me to get me a working IIgs to replace the dead one they gave me earlier... I don't imagine I can say no to a potential "kill two birds with one stone" acquisition. I'll send a PM.

(And don't get me wrong about these threads, BTW, I don't mean to sound critical of my new toys. I'm having heaps of fun looking these gift horses in the mouth.)

If you want to sell the M0131, if it's a platinum model, I'll buy it off of you.

Given how I acquired it I sort of hate to *sell* it, but if I get one of the other models I'll see how much I feel like I need it. (I do also have a Plus I can use it with.)

Tell the truth I honestly can't tell if it's beige or platinum. I want to say "beige" because I think it's slightly closer to the color of the 512k than the Plus, but it does have a gray(ish)? cable and I don't think either machine is strictly it original color. (According to the serial number decoder thing the Plus is a Mid-1987 vintage. They were done with Beige by then, correct?)

 

[Paralel]

The easiest way to tell the true color is usually to look at the feets of the drive, it tends to be the one place that doesn't chance color. The platinum models had platinum/gray feets, the beige ones had beige feets.

Also, as far as I'm aware, from what I have read on the subject, you cannot use an M0131 external drive on a 512k with stock ROMs unless it has already loaded the HD-20 init. It's a deficiency they apparently corrected with the subsequent model.

 

[Gorgonops]

I would call its feet "brown", so beige it is.

 

[Paralel]

Crud. Oh well.