jdevries@zodiac.ads.com (Jeff De Vries) (04/30/88)
The standard 7300 comes with 0.5M using 64Kbit chips. I have been told that there is space (solder pads?) on the motherboard for another 0.5M using 64Kbit chips. Is it really going to be as simple as buying some memory chips and soldering them in to get a meg? Are there any switch settings? How does the system know how much memory there is? Will it interfere with memory on the expansion bus? Has any done this already? Thanks! Jeff De Vries jdevries@ads.com /* usual disclaimer */
gsarff@ssdis.UUCP (gary sarff) (05/02/88)
In article <3645@zodiac.UUCP>, jdevries@zodiac.ads.com (Jeff De Vries) writes: > The standard 7300 comes with 0.5M using 64Kbit chips. I have been told > that there is space (solder pads?) on the motherboard for another 0.5M > using 64Kbit chips. > I have heard this several times from people here, but I have opened my unix-pc, (soon after I got it last summer) and it has 1 meg of ram and there is space (solder pads) on the mother board for another set of chips. I am pretty sure I am not mistaken, the chips say 41256 on them (can't remember if they are 120ns or 150ns) and there are 36 of them. 4 rows of 9 (making 256K with parity), when the system is booting it says something like free memory 1048576. A friend in New York bought one too and his also says this. But I remember reading the literature about the 7300 years back and it did say 512K of ram with more on expander cards. So what gives, do we have mutant 7300's? Are we using 3b1 motherboards, (which I was told were slightly different)? We also have two fans, I have heard some mention that their unixpc's have only 1. -- Gary Sarff {uunet|ihnp4|philabs}!spies!ssdis!gsarff To program is human, to debug is something best left to the gods. "Spitbol?? You program in a language called Spitbol?" The reason computer chips are so small is that computers don't eat much.
root@rocky.cs.wisc.edu.CS.WISC.EDU (Charlie Root) (05/03/88)
I think it is time to straighten this all out. Many people have posted mes- sages in the past that say that the .5MB 7300 has room for an additional .5MB of RAM, bringing you up to 1MB. NOT TRUE! The .5MB 7300 motherboard uses 72 - 4164 (64Kx1bit) DRAM chips. Since there are ONLY 72 chip spots on the UNIX-PC motherboard (same for both the 3B1 and the 7300), this is the MAX. of no waitstate, on board ram, barring any mother- board upgrades (see attmail!looney!cmv (Craig Votava)'s repost to unix-pc.gen <2634@ihuxz.ATT.COM>). The 1MB motherboard uses 36 - 41256 (256Kx1bit) DRAM chips. I do not know if it uses the 3B1 style motherboard, or if it uses the 7300 motherboard with a few jumper changes. (These jumper changes are explained in the afore- mentioned news article.) Regardless, owners of this machine can install another 36 DRAM chips, and have 2MB of no waitstate, onboard ram. Lastly, the 2MB 3B1 motherboard has 72 - 41256 (256Kx1bit) DRAM chips. This motherboard does not have any jumpers to allow for greater/lessor amounts of memmory. 2MB is the maximum amount of ram a UNIX-PC can have ON BOARD. After this, up to 2MB of add-on memory cards can be places in the expansion ports on the machine's back-side. This way, you can reach the machine's 4MB memory limit. Hope that clears up all the mud... Jonathan Sadler Computing Systems Lab (CSL) Universtiy of Wisconsin - Madison
dpb@tellab5.UUCP (Darryl Baker) (05/03/88)
In article <132@ssdis.UUCP> gsarff@ssdis.UUCP (gary sarff) writes: +>In article <3645@zodiac.UUCP>, jdevries@zodiac.ads.com (Jeff De Vries) writes: +>> The standard 7300 comes with 0.5M using 64Kbit chips. I have been told +>> that there is space (solder pads?) on the motherboard for another 0.5M +>> using 64Kbit chips. +>> No, there is space for a total of 512k using 64kx1 chips or 2Meg using 256Kx1 chips. +>I have heard this several times from people here, but I have opened my +>unix-pc, (soon after I got it last summer) and it has 1 meg of ram and +>there is space (solder pads) on the mother board for another set of chips. +>I am pretty sure I am not mistaken, the chips say 41256 on them (can't +>remember if they are 120ns or 150ns) and there are 36 of them. 4 rows +>of 9 (making 256K with parity), when the system is booting it says +>something like free memory 1048576. A friend in New York bought one +>too and his also says this. But I remember reading the literature about +>the 7300 years back and it did say 512K of ram with more on expander cards. +>So what gives, do we have mutant 7300's? Are we using 3b1 motherboards, +>(which I was told were slightly different)? We also have two fans, I have +>heard some mention that their unixpc's have only 1. Well, early 7300s had 512k then there was another option to have 1 Meg on the mother board, finally AT&T anounced the 3b1(7300++) with 2Meg on the motherboard and the hood scoop for a full height drive. As far as I know only the 3B1s only have one fan. One last note is there are several groups under unix-pc.(general,uucp,sources) You might see if these are carried by your news host. -- __ _ __ / ) // / ) / / / __. __ __ __ , // /--< __. /_ _ __ Darryl Baker /__/_(_/|_/ (_/ (_/ (_/_</_ /___/_(_/|_/ <_</_/ (_ ihnp4!tellab5!dpb / '