On 8 Sep 2008 at 15:36, Josh Dersch wrote: Take a look in the Intel Memory Design Handbook from 1973 on bitsavers. There's a whole chapter on the 1103, complete with specs: http://bitsavers.vt100.net/pdf/intel/_dataBooks/MemoryDesignHandbook_A ug73.pdf You mean that you're not going to turn your 1103 into a tie-tack or embed it in a block of resin as a keychain fob? YOU'RE ACTUALLY GOING TO USE IT?! :) Cheers, Chuck

I probably have it in dead tree format. I'll check and let you know - Ian -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Josh Dersch Sent: Monday, September 08, 2008 3:36 PM To: cctalk at classiccmp.org Subject: Datasheet for Intel 1103 DRAM? Anyone have a copy of this in digital format? Can't find this on the 'net. Trying to work out what voltages the power supply in the ND-821 is supposed to put out. From testing, it looks like 5v, 18v, and 24v. Knowing what the RAM requires will help nail this down, since it's powered separately from the main logic. Thanks, Josh

Josh, It is a little complicated, but here it is; For a straight N/C part, Vss = 16 Volts and Vbb = 19 Volts. The spec is a little hard to interpret because it says Vbb - Vss = 3 to 4 Volts. But obviously if you subtract 19 - 16 Volts you get 3 Volts. For the other versions; 1103 -1 = +19 and +22 Volts 1103 -A = +16 and +19 Volts 1103 -A1 = +19 and +22 Volts 1103 -A2 = +19 and +22 Volts Confused yet ? Hope this helps ! Best regards, Steven

I have it on paper. I've also worked on several (HP) machines that use this DRAM. The DRAMs are strange. They're PMOS, so it's really a -ve main supply (I think -16V, but that may depened on the version) and a small +ve bias supply (+3V). But often (and certainly in the HP machines I've worked on), the most -ve rail is taken as ground, so the supplies are +16V and +19V The logic levels at the address/data/control pins are also 16V IIRC. Intel did make some special interface ICs, but not everone used them. You could also use open-collector TTL buffers with an external transistor as an active pull-up, for example. The RAM signals are relatively conventional. 10 address lines, a R/W signal, data in, data out and a 'precharge' signal that isn't used on later versions (-1 IIRC) of the chip. LEt me know if you need pinouts, etc. I certainly have them, Also, you might want to take a look at the HP9810/HP9820/HP9830 schematics (on hpmuseum.net). Those machines ued said DRAM. The first 2, IIRC, used open-collector TTL chips to drive the DRAM signals and fast-ish comparators to convert the data out line back to TTL. The latter used at least one of the Intel interface ICs. -tony