demoydk@iitmax.iit.edu (Yung D. Kim) (05/03/91)
I've asked many times about memory upgrades and stuff like that...once again, I am asking that same question, but in a different context (or whatever). I have an idea about both memory upgrade and refresh rate change... Well, lets start it off with my system...I have a Tandy 1000 TL (the most limited system made on earth (I think)); it has a 8 Mhz 80286 (AMD) and uses 256K chips running at 150ns. Despite many replies of things like 'it won't work' or 'it will have an increase, but very, very little', I have thought of this: Replace all the 150ns chips with 120 or 100ns, and then change the refresh rate with a shareware program that does the 'precise' calculations automatically. I have very great doubts since I still don't know the exact limitations of my computer, but this is a shot in the dark to make the best out of a system I've outgrown (I'd like to get a 486, but being a student limits my expenditure). So, if you will, please send me comments, advise, reasonable flames that are logical in reason... Mail me at: demoydk@iitmax.iit.edu or kimyung@karl.iit.edu or kimyung@elof.iit.edu Thanks!!! *************************************************************************** Yung D. Kim "I like traffic lights" Illinois Institue of Technology "13:2.5 male to female ratio" Computer Science and Technologies "Where's my disk for my project?" WhateverNET (I forgot): demoydk@iitmax.iit.edu "The Encore/MADMAX/IITMAX" Another source <======> kimyung@harpo.iit.edu "The VAX Marx brothers" "Bump a bump if you don't feel it" <================================ B.I.P. "All we are...is dust in the wind, dude" "Ted" Theodore Logan "All we are...is all we were less all we will be." Some dude named Donovan ***************************************************************************
jgraf@pollux.svale.hp.com (John Graf) (05/09/91)
Changing the refresh rate will NOT buy you any performance gain. The only reason to put faster-access DRAMs in your system is if you can also decrease the number of wait-states added to memory cycles by the DRAM controller. Typically the wait-states are hard-wired into the DRAM controller (they assume a certain speed DRAM), but some controllers have programmable wait-state registers. You should try to get a Technical Reference Manual from Tandy (if one exists) to find out if there's any way to change the wait- states. If you can't change 'em, don't waste your money on the faster DRAMs -- your system will still assume you have the slow DRAMs. Regards, John Graf 8v)
poffen@sj.ate.slb.com (Russ Poffenberger) (05/16/91)
In article <6710006@pollux.svale.hp.com> jgraf@pollux.svale.hp.com (John Graf) writes: >Changing the refresh rate will NOT buy you any performance gain. >The only reason to put faster-access DRAMs in your system is if >you can also decrease the number of wait-states added to memory >cycles by the DRAM controller. Typically the wait-states are >hard-wired into the DRAM controller (they assume a certain speed >DRAM), but some controllers have programmable wait-state registers. >You should try to get a Technical Reference Manual from Tandy (if >one exists) to find out if there's any way to change the wait- >states. If you can't change 'em, don't waste your money on the >faster DRAMs -- your system will still assume you have the slow >DRAMs. > Agreed that putting faster DRAMS than necessary in a machine is a waste of money since the access is fixed byt the number of wait states. However, changing the systems refresh interval CAN cause a small, but perceptible increase in performance. During refresh, the CPU is locked out from ALL memory access, increasing the delay between successive refreshes will allow the CPU to access memory with fewer delays. There are several PD programs available to change the refresh interval. You do run the risk of getting more memory errors if the interval is set too large. Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen 1601 Technology Drive CIS: 72401,276 San Jose, Ca. 95110 (408)437-5254