lphillips@lpami.vnet.van-bc.UUCP (Larry Phillips) (11/16/87)
There seems to be a persistent notion that the expansion slot on the A500 is both backwards and upside down. This is most definitely not the case. The connector is backwards, but right side up. Pin 1 is on the top of the motherboard and toward the rear of the A500. The main obstacles to expanding the A500 are: 1. Available power. All expansions drawing more current than a simple ROM cartridge will need a separate power supply. 2. Physical considerations: a. Height of the expansion connector b. Depth expansion connector is recessed from edge of case. 3. The same consideration as the A1000 _should_ have been given with regard to SOTS vs. expansion chassis. The above points should only affect existing A1000 peripherals, since all new expansion devices will be properly designed. -- 1/2 :-) -- <slight flamage ahead> In the same vein, please be aware that the "let's do it cheap and not bother telling the customer" mentality has already struck the first blow in the A500 arena. The Spirit Technologies internal 1.5 meg expansion will most definitely overtax the power supply, and flat should not be considered for the A500. As might be expected from a company who would do this, they blame CBM for not supplying enough power, and if you complain loudly enough, will tell you to purchase a beefier supply. They also claim that it is CBM's fault that only 1 meg of their 1.5 meg expansion will autoconfig, and that this will be 'fixed' in an upcoming release. Personally, if smeone gave me one of their products, I would dismantle it for parts. <end of flamage, resume normal speed> Larry. -- +--------------------------------------------------------------------+ | Opinions? I had some around here somewhere... | | // Larry Phillips UUCP: lphillips@lpami.vnet.van-bc.UUCP | | \X/ or: {ihnp4!alberta!ubc-vision,uunet}!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 | +--------------------------------------------------------------------+
bryce@hoser.berkeley.edu (Bryce Nesbitt) (11/17/87)
In article <1540@van-bc.UUCP> lphillips@lpami.vnet.van-bc.UUCP (Larry Phillips) writes: > ><slight flamage ahead> > In the same vein, please be aware that the "let's do it cheap and not >bother telling the customer" mentality has already struck the first blow >in the A500 arena. The Spirit Technologies internal 1.5 meg expansion will >most definitely overtax the power supply, and flat should not be >considered for the A500. Yes, that is a nasty thing to do to users. However if you assume that any side expansion device will be self powered, there is no internal helf-fast ram and no external disk drive or connector takes power from the computer you are not exceptionally out of spec. Be sure to use "standby" power for 2 of the ram banks and "operating" for the remaining one. Typical for a dram is about 22mW standby and 350mW operating (rough figures). Not that the Spirit people would mention this if you asked them. Or warn the customers to calculate a power budget. >As might be expected from a company who would do >this, they blame CBM for not supplying enough power, and if you complain >loudly enough, will tell you to purchase a beefier supply. Oh, really. Is such a supply even available for plug and play on the A500? >They also claim >that it is CBM's fault that only 1 meg of their 1.5 meg expansion will >autoconfig, and that this will be 'fixed' in an upcoming release. But it *is* due to a bug. Kickstart V1.2's memory sizer will puke on an exactly 1.5 meg $C00000 board. 1.75 or 1.25 meg is ok. Seems it hits the A500 clock module. (The sizer also wipes out memory needlessly (It could have been done without destroying memory -or- reading from write-only registers)) You can probably get the memory back with some kludge like: addmem 0xD40000 0xD7FFFF Or something close to that. I don't have one of these things, so this may be a bit skewed. On the A1000 memory board they use the *OVR signal for memory arbitration, and don't do anything special to it. This is most specifically forbidden by C=, and on top of that they did not take any special precautions to make it work reliably. The FCC shield inside the Amiga will not close with the Spirit A1000 board installed. They don't include a motherboard ground clip. (Adding one helps improve the reliability) It is sort of amusing to note that for a company doing so many "cheap" things, they include a very expensive clock chip. For all that extra money, it is incompatible with the A500/A2000's and has 2K of totally useless battery backed ram. (Go ahead.. I dare you. Find a use for that memory. I can think of one, and it is not much of one at that) Disclaimer: I did some contract work for them once. I have no gripes with them other than the 1.5 Meg ram board I got as part of the deal crashes every so often. I don't wish bad things to happen to them, but I have a problem with any company that produces defective products shamelessly. >Personally, if smeone gave me one of their products, I would dismantle it >for parts. Exactly what I had in mind. Now if I could only find a Zorro II board that uses ZIPs 1/2 :-). |\ /| . Ack! (NAK, SOH, EOT) {o O} . bryce@hoser.berkeley.EDU -or- ucbvax!hoser!bryce (") U
ptp6186@ritcv.UUCP (Paul T. Pryor) (11/18/87)
In article <21822@ucbvax.BERKELEY.EDU> bryce@hoser.berkeley.edu.UUCP (Bryce Nesbitt) writes: > [text deleted] >Oh, really. Is such a supply even available for plug and play on the >A500? > Yup. Saw an ad in the latest Info magazine by Phoenix Electronics for an replacement A500 power supply ($100 I THINK). Sorry, didn't have the magazine with me. If anyone is interested, I can post it here. I'm not affliated in any way with Phoenix Electronics. Or you could purchase a cheap switching power supply ($40 to $70) with about seven amps of 5VDC (much more than the measly 4.5 amps 5VDC provided by CBM's version). But you would have to come up with a connector to plug into the power jack on the A500. Just check any Computer Shopper out for the power supply bargains. On another issue, I was not really satisfied with the 1 meg of memory available on my A500 ... I am *seriously* contemplating doing something (akin to Chris Erwin's hack) to add 512k or 1 meg to my Amy. But with a new twist - auto configuration, if it is feasible. I'm still doing my feasiblity study. Anyone care to comment ? I can go over several issues in the area of memory upgrade hacking, but I need to know if anyone is interested ... Paul T. Pryor Boy, do I love hardware hacking ! *------------------------------------------------------------------------------* | UUCP: {allegra,seismo}!rochester!ritcv!ptp6186 | | ARPANET: ptp6186%rit@csnet-relay | | BITNET: ptp6186@ritvax.bitnet | *------------------------------------------------------------------------------*
cp50@sdcc15.UUCP (11/21/87)
In article <803@ritcv.UUCP> ptp6186@ritcv.UUCP (Paul T. Pryor) writes: >In article <21822@ucbvax.BERKELEY.EDU> bryce@hoser.berkeley.edu.UUCP (Bryce Nesbitt) writes: > >On another issue, I was not really satisfied with the 1 meg of memory >available on my A500 ... I am *seriously* contemplating doing something >(akin to Chris Erwin's hack) to add 512k or 1 meg to my Amy. But with a >new twist - auto configuration, if it is feasible. I'm still doing my >feasiblity study. Anyone care to comment ? Actually, I'm a friend of Cris Erving's, and I asked him about an internal memory upgrade for the 500 beyond 1 meg. Apparently, there is not enough power to drive additional memory. A few Commodore folks have also been overheard confirming this. Not to badmouth commercial products, but I personally would not go near any of the "total 2.5 internal meg RAM for your 500!!!" boards... -Stephen Hartford cp50%sdcc15@sdcsvax