RE: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread D. Resor via cctalk
I've taken and uploaded some larger easy to view images of the processor board component and solder sides. One plus is the eproms are socketed. I've uploaded an image showing the silk screening stamp on the underside of the eproms. Now that I look closer at the Power Supply PWB I see it too

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Paul Berger via cctalk
The only new information I can gather from those picture is it would appear that pins 1 and 28  of the EPROMs is tied together and since 28 is Vcc, connected to +5V this would eliminate 27512 as pin 1 on a 27512 is A15, but on 2764, 27128, and 27256 it is Vpp and would normally be tied to +5V f

Searching cctalk archives?

2022-03-22 Thread Tom Hunter via cctalk
I came across a reference to a cctalk message from 9 September 2006 and would like to read the rest of the thread with the subject "PDP-8m Console Switch Problems - fixed!". Unfortunately it appears that the cctalk archive does not go back to 2006. Is there some place with the complete cctalk arc

Re: Searching cctalk archives?

2022-03-22 Thread jim stephens via cctalk
On 3/22/2022 9:23 AM, Tom Hunter via cctalk wrote: I came across a reference to a cctalk message from 9 September 2006 and would like to read the rest of the thread with the subject "PDP-8m Console Switch Problems - fixed!". Sending you the requested month.  many titled messaages. will send

RE: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread D. Resor via cctalk
There are a few other problems. The power supply does not power up. Three of it's four voltages are missing (+5vdc, +8.5vdc, +13vdc). With no connections to the power supply board, the +5vdc measures 4.92vdc while the other two voltages are still zero volts. The second issue I found upon remo

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Paul Berger via cctalk
You are correct ordinary glass does not transmit UV well, the UV lamps normally used to erase EPROMs and germicidal lamps like the window in an EPROM are made from quartz glass. Florescent lights do leak a little UV but it would take a long time to erase an EPROM. Paul. On 2022-03-22 06:40, D

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread dwight via cctalk
It is true that the glass blocks most of the UVC from florescent lamps. The key word here is "most". It is not a 100% block. When looking at aged data in EPROMs one should error on the side of caution. As an example, I have a pole lamp that I use a standard florescent bulb, with the typical spira

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Chris Elmquist via cctalk
On Monday (03/21/2022 at 09:17PM -0700), Glen Slick via cctalk wrote: > On Mon, Mar 21, 2022 at 8:25 PM Chuck Guzis via cctalk > wrote: > > > > The PROMs are most likely house-labeled Intel commodity parts with > > JEDEC-standard pinouts, so it should be fairly easy, using an EPROM > > reader, to

Re: Unusual “gold” IC chips?

2022-03-22 Thread Magnus Ringman via cctalk
Those look like "stripline" RF/microwave packages. PCBs will have cutouts for the package body, so that the leads can be soldered flat (no bends) directly onto impedance-controlled leads on the board. On Tue, Mar 22, 2022 at 6:17 PM Oldcompu via cctech wrote: > Anybody know what these are? Mayb

Re: Unusual “gold” IC chips?

2022-03-22 Thread Paul Koning via cctalk
> On Mar 22, 2022, at 1:25 PM, Magnus Ringman via cctech > wrote: > > Those look like "stripline" RF/microwave packages. PCBs will have cutouts > for the package body, so that the leads can be soldered flat (no bends) > directly onto impedance-controlled leads on the board. > > On Tue, Mar

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Glen Slick via cctalk
On Tue, Mar 22, 2022 at 11:56 AM Chris Elmquist wrote: > > Trying not to hijack the thread too much but I have an Intel D27C256-200 > here in my TL866II+ programmer and it returns ID 89h / 8Dh. > http://www.bitsavers.org/components/intel/_dataBooks/1993_Intel_Memory_Products.pdf Page 5-78 (Page

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Chris Elmquist via cctalk
On Tuesday (03/22/2022 at 12:20PM -0700), Glen Slick wrote: > On Tue, Mar 22, 2022 at 11:56 AM Chris Elmquist wrote: > > > > Trying not to hijack the thread too much but I have an Intel D27C256-200 > > here in my TL866II+ programmer and it returns ID 89h / 8Dh. > > > > http://www.bitsavers.org/c

RE: Searching cctalk archives?

2022-03-22 Thread pbirkel--- via cctalk
In general: http://bitsavers.org/mailing_lists/cctalk_mailing_list/ However I just used Google Search on "PDP-8m Console Switch Problems - fixed! CCTALK CCTECH" and the fourth hit was: http://bitsavers.org/mailing_lists/cctalk_mailing_list/2006-September.txt Then search in that page for "PDP

DEC DC319A DLART (DL11 Compatible Asynchronous Receiver-Transmitter)

2022-03-22 Thread pbirkel--- via cctalk
In case anyone else has been looking some of these, there is a listing for multiple tubes-of-11 on eBay at a moderate price: https://www.ebay.com/itm/123710245814 QTY-11 PCS. AMI SEMICONDUCTOR DC319 C04090 Integrated Circuit - (UIC 40378901) It's documented in the DEC Semiconductor

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Paul Berger via cctalk
I can tell you what some of the chips are on the power supply board, but the list I have is mostly TTL parts 1582684 LM324 1582606 74LS74  F/F D-TYPE DUAL +E/T 2392122 7417    BUF/DVR HEX O/C (TPD0 30NS) 8272147 74LS05  INV HEX O/C Aside from the house numbering of parts which is no

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Glen Slick via cctalk
On Tue, Mar 22, 2022 at 12:25 PM Chris Elmquist wrote: > > On Tuesday (03/22/2022 at 12:20PM -0700), Glen Slick wrote: > > On Tue, Mar 22, 2022 at 11:56 AM Chris Elmquist wrote: > > > > > > Trying not to hijack the thread too much but I have an Intel D27C256-200 > > > here in my TL866II+ programm

Re: Searching cctalk archives?

2022-03-22 Thread jim stephens via cctalk
sorry to put on list, but never heard from Tom about what I sent him. thanks Jim On 3/22/2022 9:23 AM, Tom Hunter via cctalk wrote: I came across a reference to a cctalk message from 9 September 200

Re: Searching cctalk archives?

2022-03-22 Thread Tom Hunter via cctalk
Thank you Jim and Pbirkel for your help. Sorry for the slow reply. I live on the west coast of Australia in Perth (GMT+8) so our time zones differ a lot. Best regards Tom Hunter On Wed, Mar 23, 2022 at 11:25 AM jim stephens via cctalk < cctalk@classiccmp.org> wrote: > sorry to put on list, but

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread dwight via cctalk
Years ago when I was at Intel, they would take EPROMs that had only a few defects and attempt to program them with specific applications. They would then usually paint the window black and put on that particular product number. When we needed EPROMs in the lab, we would take a pile of these that

Re: ID UV erasable PROMS used on an IBM PC board?

2022-03-22 Thread Chuck Guzis via cctalk
On 3/22/22 21:32, dwight via cctalk wrote: > Years ago when I was at Intel, they would take EPROMs that had only a few > defects and attempt to program them with specific applications. They would > then usually paint the window black and put on that particular product > number. When we needed EP