Here is an Excel spread sheet that list most of the parts needed for the S100 boards in a Z80 system with cost for each part. its not 100% correct, but pretty close... very easy to add more boards if needed! For parts I did not have, I use Avnet Express where I could, very good pricing on most items!!! Reasonable shipping and quick... Much better pricing that Mouser, Digikey and most of the "surplus" stores... and the parts are NEW. enjoy... tom... On Thu, Jun 21, 2012 at 6:29 AM, John Monahan <mon...@vitasoft.org> wrote: > Just use 1K > > > From: John Monahan Ph.D > e-mail: mon...@vitasoft.org > Text: mon...@txt.att.net > > > -----Original Message----- > From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On > Behalf Of Paul Birkel > Sent: Wednesday, June 20, 2012 10:37 PM > To: n8vem...@googlegroups.com > Subject: Re: [N8VEM-S100:874] 1.1k 10-pin Resister Pack supplier (or > alternative values)? > > Thanks Tom, John. Doing the verification part here before the testing :->. > We need to collect these sorts of "tweaks that work" for the various boards > in appropriate locations methinks. > > John: While I've been reading up on the various calculations regarding the > selection of o.c. pullups and fanout/in calculations (Wilcox Section 3.1.1 > is quite good) I haven't found anything specific on the selection of > open-input pullups. Recommendations? > > On Wed, Jun 20, 2012 at 11:38 PM, John Monahan <mon...@vitasoft.org> wrote: >> Paul this question has come up before. There is nothing special about >> the 1.1K value of the pull-up resistors for the TTL circuits. 1K will >> be fine, as would the more common 1.2K types. Jameco used to sell >> 1.1K's but no longer do. The choice of value for pull-ups like that >> is a balance between noise immunity (low values, ~1K) to power >> utilization (high values ~2K or even 4.7K). Other factors are signal > pulse width and fan-out. >> >> John >> >> >> >> From: John Monahan Ph.D >> e-mail: mon...@vitasoft.org >> Text: mon...@txt.att.net >> >> >> -----Original Message----- >> From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] >> On Behalf Of Paul Birkel >> Sent: Tuesday, June 19, 2012 10:32 PM >> To: n8vem...@googlegroups.com >> Subject: [N8VEM-S100:870] 1.1k 10-pin Resister Pack supplier (or >> alternative values)? >> >> The S-100 MSDOS Board, Z80A Master CPU Board, and Serial I/O Board all >> specify the use of a 1.1k 10-pin Resister Pack. >> >> This seems to be an uncommon part. Is there a recommended supplier? >> >> Alternatively, is the value critical in these three board-uses? >> >> The S-100 MS-DOS Board uses a pair of packs (RR7/8) as input pull-up >> resistors on the two 74LS165 address decoders. The Z80A Master CPU >> Board similarly uses three packs (RR3/4/7) as input pull-up resistors >> on its three >> 74LS165 address decoders. It seems to me that in this use the values >> are fairly non-critical. What is the recommended, commonly-available, >> alternative resistor value? >> >> The Serial I/O Board is a bit more complicated. It uses a single pack >> (RR1) which connects to PU1K-A thru PU1K-I. >> >> 1. PU1K-A/B/C are used on the Z8530 UART_INT*, UART_IEI, and >> UART_INTA, apparently as input pull-ups. >> 2. PU1K-E/F are used as pull-ups on two outputs of a open-collector >> 74LS06N (the other 4 outputs are spares). >> 3. The remaining 4 pack-resistors are spared. >> >> Given this mixed-use, what would be the recommended, >> commonly-available, alternative resistor value? Or should I consider >> hand-wiring single resistors in each case -- and then what would be >> the recommended values in each case (UART input pullups; o.c. >> pullups)? >> >> Thanks! >> >> paul >> > -- ~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~ Tom Lafleur (858) 759-9692
Attachment:
S100 Project Parts.xls
Description: MS-Excel spreadsheet