A500 memory expansions and A590 HDD

[Solo761]

Hello, my first post here . I got an opportunity to buy A500 and A1200 with few extras and I took it . They're work fine but I'm going to check them anyway. First one on dissecting table is A500 .

1. It had RocTec RM550C-F memory expansion but I noticed that battery on it has leaked so I took it out just to be safe until I find a replacement battery.

How to clean this leakage in safest way for remaining electonics? I planned to do this with alcohol, but better to be safe than sorry.

I googled for replacement battery but it seems this exact one (2/V60R) isn't available any more. Now it's called 2/V80H, main difference I noticed is that it's NiMH instead of NiCd, will this be a problem?



2. With all the stuff I got with these Amigas I also got another memory expansion board for A500, JEC-910701. Compared to the one I pulled from A500 this one looks more amateurish made. Crystal looks "funny", like burnt on the side, but that could be simply crappy soldering.
Would it be safe to try if it's working by plugging it in expansion port? Or it's better not to mess with it?


Is there somewhere a site with manuals for these expansion boards?

I only found them mentioned

JEC - http://amiga.resource.cx/exp/jec512
RocTec - http://www.bigbookofamigahardware.co...t.aspx?id=1064

I guess there were too many different ones to be kept on sites like

http://amiga-manuals.xiik.net/


3. Last interesting piece is A590 Hard Disk expansion. It has some simple issues (wires from the status leds fell off, but that's easily fixable), but the main one is that hard drive inside it crapped out. After all, it is slightly ancient . It has Epson XT IDE 20 MB hard drive. From what I googled this old IDE standard won't work with IDE to CF cards.
But there's also SCSI connector. Did someone try cheap SCSI to IDE adapter on it? Something like this

http://www.ebay.com/itm/SCSI-80-68-5...item2a30977210

Although, when I look at it it's doubtfull. It looks like simply rewire from SCSI connector to IDE connector, without any electronics to translate from standards :/.

I looked on ebay for HDDs but smallest they had were 9.1 GB and I read somewhere 1 GB was largest that can go in this bay.

There are other SCSI to IDE adapters, but they're a bit pricey, 100+ dollars.


That's all for now, I guess there will be more questions, but I do try to research it myself first

[GadgetUK]

Alchohol (Isopropanol) is fine. Some people stick PCBs in dishwasher. Make sure it's completely dried off. NiMh is fine - don't solder directly onto the PCB, what many people do is put 2 wires on the PCB to the battery, and stick the battery in a ziplock bag stuffed somewhere in the expansion area. That way it won't leak onto the PCB in future.

You can try that other memory expansion OK - I would clean it up first.

No idea about the HDD. Is it MFM or definitely IDE? I would attempt fitting a CF card personally to see if it might work.

[GadgetUK]

Edit: using SCSI to IDE adaptor might not help. I assume you would want to connect a SCSI drive to the IDE connector the HDD is currently using? If its an early IDE implementation that doesn't work with CF drives it might also not work with newer SCSI drives. On that pic it shows SCSI port - try connecting a SCSI drive directly to that.

[Solo761]

Okay, so today is the cleaning day . I prefer to clean electronics carefully bit by bit. I hope it didn't corrode much through traces on PCB. It doesn't look too bad. It's only few mm around the battery. After I clean it I'll spray it with pcb lacquer. That'll help protect it.
Good idea with ziplock bag. Maybe even use glue gun to secure it around the wires to be sure that it doesn't leek out in the future.

Yup, again with alcohol. So, it should be safe on Amiga? I'm afraid to kill it so soon .

Manual calls it "XT interface for IBM PC XT bus type drives". From what I read it's grandpa from usual IDE standard and not compatible with those IDE to CF adapters and memory cards. Although I'm not in a hurry. I've ordered one for A1200 so I'll probably try it in this one.

Thanks

Originally Posted by GadgetUK

Edit: using SCSI to IDE adaptor might not help. I assume you would want to connect a SCSI drive to the IDE connector the HDD is currently using? If its an early IDE implementation that doesn't work with CF drives it might also not work with newer SCSI drives. On that pic it shows SCSI port - try connecting a SCSI drive directly to that.

Currnet hard drive is connected to to this so called XT IDE and the other one is SCSI. From what I read so far this "old" XT IDE standard doesn't support CF cards.
But it should be possible to connect it to that SCSI connector using SCSI to IDE adapter, but that adapter from ebay link is just that, adapter from one connector to another connector. But to really convert from SCSI to IDE you need some logic to translate from IDE to SCSI command set and vice versa. Those kind of adapters are kinda steep.

Hmm, I just remembered I have one old WD IDE 3.2 GB hard drive laying somewhere. Maybe it'll work with this. It's about 15 years old, at least 10 years since I last used it, but it worked then, maybe it's still alive.

[alexh]

I think you're right about the 8-bit XT-IDE (XTA) connector not working with IDE->CF cards. You could ask Zetr0 as he's the master of these. He made an XT-IDE interface for the Spectrum.

The A590 SCSI connector works with a SCSI->IDE(->CF) adapter.

You are correct. That ebay auction is not a SCSI->IDE adapter. It doesn't even have an IDE connector. It's a SCSI->SCSI adapter.

If you replace the A590's ROM with a v7 ROM and patch your OS filesystem (FFS v44.5+) you can use hard-drives greater than 1Gb with A590.

[Solo761]

Interesting... I removed the hard drive (it's really a piggy, it's almost twice the height of what we today consider standard 3.5'' HDD ) and looked at it's mobo.

From what I figured 390388-01 and 390389-01 chips are ROM chips, U12 file goes in 88 chip and U13 goes to 89 chip (according to http://mhv.bplaced.de/cbmroms/cbmroms.php ) and chip types are EPROM 2764, cheapest programmer for them found is Top 853, but if I go that route I think I'll try to find someone who has programmer already. $30 is not that much but then again, for one time use... Too bad it doesn't support PICs or Atmegas as I could use it for them.

I'll have to investigate it some more. Post #9 from ROM topic says v6.6 supports partitions up to 1 GB. For A500 I think that's plenty. If I could use 4 or 9.1 GB SCSI disc with one 1 GB partition that would be fine by me.

*edit*

I was just though of something in regard to RM550C-F memory expansion board and it's battery. Replacement 2/V80H is rather pricey, and it's really just 2.4V NiMH battery, actually two 1.2V cells (V80H) of 40 mAH. One could solder something more common. Like two NiMH 1.2 AAA cells. Only problem I can think of is capacity. Two AAA cells have significantly bigger capacity than 2/V80H cell. If they get charge from expansion board I'm afraid it could cause damage. Any thoughts?

[alexh]

Looks like you have a very early ROM. You may as well go for v7 as an upgrade.

A590/A2091 SCSI boot ROM ??? (U12) --> 390389-01
A590/A2091 SCSI boot ROM ??? (U13) --> 390388-01

A590/A2091 SCSI boot ROM 5.92 (U12) --> 390509-01
A590/A2091 SCSI boot ROM 5.92 (U13) --> 390508-01
A590/A2091 SCSI boot ROM 6.0 (U12) --> 390388-03
A590/A2091 SCSI boot ROM 6.0 (U13) --> 390389-03
A590/A2091 SCSI boot ROM 6.1 (U12) --> 390722-01
A590/A2091 SCSI boot ROM 6.1 (U13) --> 390721-01
A590/A2091 SCSI boot ROM 6.6 (U12) --> 390722-02
A590/A2091 SCSI boot ROM 6.6 (U13) --> 390721-02
A590/A2091 SCSI boot ROM 7.0 (U12) --> 390722-03
A590/A2091 SCSI boot ROM 7.0 (U13) --> 390721-03

[Toni Wilen]

ROM update is not needed to access >1G drives if you use PFS3DS (or pfs3-aio) filesystem. (Unless pre-6 ROMs have other bugs)

[Solo761]

Ouch, I hoped it's a bit newer than that . Maybe I'll fork up for the programmer after all. Hopefully I'll find someone with a programmer nearby. Maybe that's the best option since current ones must be erased first and I don't have UV eraser. I doubt something like this would be enough

[Solo761]

I've need an advice for rom burning. I've got my hands on GQ-4X programmer, I also got A590 v7.0 rom files, but instead of M2764(A) EPROMs I have M27128A EPROMs which are 128k instead of 64k. From datasheet I see pinout is almost the same, M27128A has A13 line on pin 26 while M2764 doesn't use it.

Now, can I use M27128A insted of 2764? Like you can use 27C400 on A1200 by concatenating splitted kickstart roms to use full capacity? Ie, can I just concatenate each of two A590 rom files and burn them to M27128As?


Also, since GQ-4X programmer can burn 27C400 and it's variants I'm thinking on getting 16 bit adapter to be able to do so. Mcumall 16 bit adapter is kinda pricey. Can GQ-4X use other willem adapters? Like sivava 16 bit willem adapter? It's cheaper than original mcumall one. But on pictures it also uses some ribbon cable in adition to socket, this ribbon cable goes from adapter to sivava willem programmer. GQ-4X is enclosed, it only has ZIF socket. Does this adapter work on GQ-4X or it's sivava only? I couldn't find any info on this on the net.

[Jope]

Yes, just concatenate.

It's best to err on the side of caution with Willem derived programmers. Many of them are derived quite far and thus the adapters are a bit custom too. I'd buy the MCUMall adapter in this case.

[Solo761]

Thanks, on both accounts.

I'll think about getting that adapter or not. It costs $29 and shipping from Canada is additional $44, a bit too much for an adapter :/. Maybe I'll make my own in the end, I have the schematic of this specific one.

[Jope]

As long as the adapter doesn't require additional address line wires, then you might be ok using an adapter made for a different Willem. If it does, the GQ-4X doesn't expose those address lines to separate jumpers, you need to reverse-engineer MCUMall's adapters to figure out which pins on the socket they are using.