Re: Reading/Verifying the Intel 8041A
On 05/20/2015 7:15 PM, Richard B. Main, Esq. wrote: The Intel AFN-00188B Datasheets for 8041A/8741A specify that EA max is 24.5V. The verify mode for PROM/ROM holds EA high at 23V. The 8048/8748 Datasheets say EA is 32V for 8748 Verify but need only be +12V for 8048. Richard Speaking of old textbooks, something people need to keep an eye out for are old parts catalogues put out by the large parts distributors of yore. I have an Electrosonic Catalogues (Canada - 600 some pages of components!) from the late 60s and it is great because they have unarchived specifications on many of the early solid state and EM parts - many of which are used in older computers. One spec sheet I found was a comparison sheet of CDS cells that were common in 1969 and gave their range of specs - handy! The advantage for me is I use these to get the specs on old parts that I am trying to repair, or replace with more modern parts. At one time E-Sonic had a few PDFs of these early manuals online, but they seem to have hidden them since the last time I visited their site. And I just did a bit of a search using Archive.org's wayback machine and can't find the year when they did have those on their site... John :-#)#
Re: 54 TK50 tapes on eBay
Am 20.05.15 um 21:11 schrieb Johnny Billquist: Hmm. There might also be other issues when using a TZ30 as compared to a TK50 here... I don't even remember how the TZ30 looks inside. There might be rubber parts in there. No rubber. The tapes got stuck to the read-/write head. -- tschüß, Jochen
hp 1820-7730 datasheet? HP-PB J2146A LAN interface, SOT23 part missing
Hello Folks, with a bunch of HP 9000 equipment, I received a HP-PB 802.3 10Mbps LAN card that was missing the 10base2 BNC connector and the SOT23 SMD part directly behind it. No idea why and by whom they were removed. A BNC socket was easily found in one of my parts bins, but what about the SMD component? My first idea was this might just be some sort of transient protection device (I've seen a really old ISA NIC fitted with a neon bulb next to the BNC for that purpose!) but there probably is a bit more to it, as pin 1 connects to BNC Center and to pin 7 on the PHY (U18, NatSemi SS9130AP also HP house-marked as 1820-7730), pin 2 is BNC shield/ground *and pin 3 goes to pin 5 on the PHY*. Unfortunately I was not able to find a datasheet for the PHY that would probably give an example circuit - can anyone please either point me to that or, if they have an example of that card available, look up the marking of that SOT23 device for me? Card would be for my HP9000-K100 PA-RISC, for which I'm also looking for one of the graphic options. One keeps popping up in the US 'bay but the (commercial) seller wants real money for it - add SH to old europe and it's waaay out of my confortable range. Thanks in advance, Arno
