Skip navigation

A Packard Bell 486 PC. probably with an almost identical layout to other PB machines of the same era but with a different name. This particular machine was picked up by a friend of mine for $8. You may also be seeing it in a later review significantly reconfigured for a particular purpose but as of now were going to be looking at its (mostly) stock configuration.

pbl1151

Stock this PC is actually rather light and small making it a decent 486 for a non power user that just may want a compact 486 for dos gaming and doesn’t care about having a massive dos monster machine. The downside is the lack of expansion bays. As for external bays we just have one 3 1/2 inch and one 5 1/4 inch bays. Mine came with a standard 1.44mb floppy drive but the upper bay can be used for a CD-Rom drive or a 5 1/4 floppy drive. I like how the cover for the upper bay kind of looks like a disk drive. Besides the power button on the right of the floppy drive we have two lights labeled HDD for hard drive activity and a turbo light but no turbo button. Like the earlier PB 500 I reviewed the Legend 115 actives the turbo by the keyboard and pressing [Ctrl]-[Alt]-[ – ] to slow the PC down and [Ctrl]-[Alt]-[ + ] to restore normal speed. The light should change color to indicate if turbo is activated or not but if it is you should defiantly notice. Like many 486 machines of the time “turbo” buttons now slow the PC down as opposed to speed it up. This is to help with compatibility with older games that require slower CPU speeds. With my turbo activated my machine acted more like a 286 class PC.

As opposed to having screws in the rear to secure the case cover There are two hidden latches in the front that cover the screw placement. I kind of like this. its convenient and looks nice.

pbl1156

Turning the PC around we see.

pbl1152

Slots for three expansion cards, again a bit limiting but not horrible. From the right we have a I/O serial port and then a printer port. This followed by a game port for a controller or joystick which is kind of nice to have built into an old system. Next to that is a VGA port and then two PS/2 ports for your mouse and keyboard, again nice to not have to deal with an AT keyboard keyboard and serial mouse.

pbl1153

Opening up the system is a simple as taking out the two front screws and sliding the top case off. You can see the hard drive in the upper part of the image. It mounts on a slide in a side position. For a better view of the board you have to remove the middle cross bar. Its easy just two screws and then remove the ISA riser. This model is limited to three 16 bit ISA cards which is going to limit what you can add especially if you wanted to go for a fast VLB video card. It gets even more cramped if you want to add modem or network cards though I believe there are models very similar to this with built in modems. The covered port and connectors are on this model on the other side of the riser.

pbl1154

This machine uses the 410/42/420t m motherboard. Specs can be found here

1) These are the connectors for the single IDE channel and behind it in the picture is the connector for the floppy drive cable. There just pins with no plastic guide guard around them so you need to be a little careful. I also should say the BIOS for the IDE is VERY picky about what hard drives will boot and work. Mine came with a completely dead 140mb Conner IDE drive. Unfortunately the BIOS has no auto IDE detect and even if you know your drives parameters I could not get it to work correctly with any newer IDE drives I owned. The only drive I got to work was on old 420mb Conner IDE drive that had the drive parameters printed out on the side of it.

2) The CPU that came with this machine that you see here is an Intel 486 25mhz SX. Its a slightly unusual part. The SX designated that there is NO math co-processor on board. Luckily this motherboard supports a wide array of CPU’s selectable via jumpers on the board. there should be a label on the underside of the removed case cover with a jumper guide. The 486-25SX is pretty slow as far as 486 CPU’s go but its reliable and does not require any kind of heat sink or fan. Apparently a lot of these chips were actually 33mhz parts down clocked with the math co disabled. You have to love Intel. This being said there usually pretty overclockable but in these days its just easier to actually buy a higher clocked chip.

pbl1155

If the blue socket didn’t tip you off you can take the chip out of the socket and can see this is actually a Intel overdrive socket and so compatible with a Pentium overdrive CPU which would in theory bring this machine up to early Pentium CPU speeds of 63 to 83mhz.

3) Here we have the soldered on 4mb of RAM and a 72 pin RAM socket. This machine did not come with the RAM slot populated, I had added the RAM stick. As I said the machine does come with 4mb of RAM on the motherboard which is nice. The motherboard can take a 32MB stick for a total of 36MB of RAM.

4) The onboard Video is run by a Headland Technology video chip with 512kb of video RAM. I cant seem to find much information on this company or the quality of there video chips but from the information, or rather lack of information I don’t imagine they were a major player or well known for high quality. The chip is apparently running on an integrated VLB bus though and benched slightly higher then a et4000ax and diamond speedster pro I had installed via the ISA slot in tests. upgrading to 1MB of video RAM looks possible via a proprietary looking socket.

*I was recently informed that the Headland chip in the Packard Bell does have a timing error that causes graphical errors such as dot trails and graphics corruption in some games, Sim City 2000 being one of them and Ultima VII being another as yet I have not confirmed this in Sim City but Ultima VII definitely has graphical issues with the on board video.

5) These are the sockets for the L2 cache. Cache is basically very fast RAM that the CPU accesses first before going to the comparatively slower system RAM. The L1 cache ram is generally located on the CPU itself in small amounts but in the 486 era the L2 cache RAM was added and placed on the motherboard usually close to the CPU socket. L2 cache is slower then l1 cache but much faster then the standard RAM, also it was pretty damn expensive. sometimes less reputable PC motherboards either came with completely fake L2 chips, empty and none functioning sockets or lucky in this case simply empty sockets. Even though this PC comes with no L2 cache if you can find the chips 32, 128 or 512k of L2 cache RAM can be added for a nice performance boost. 512k is kind of a lot so I’m a tad impressed with that.

pbcache

On the left is a cache chip of the size if you want 64 or 128kb of L2 cache. The chip on the right is the larger size that you will need if you want 512kb of cache. these larger chips seem harder to find and even when I did find a number of them when I tried them they failed to work.

For a lowly Packard Bell this PC isn’t to bad. I do have some issues with the video, the small number of drive bays and lack of anything other then 3 ISA slots is limiting and the BIOS is very picky about hard drives. That said the CPU upgradability is decent the 72 pin RAM is pretty expandable and the option to add a good amount of L2 cache is a boon. All in all I think it makes a decent 486 for the casual user that’s not concerned with having the most powerful 486 and has little space to spare. I myself am planning a future article using this machine in a configuration for a  special purpose.

Benchmarks (Intel SX 25mhz 486, 128kb L2 Cache, 20MB FPM RAM, Built in Headland 512kb video)

3DBENCH – 19.9

PCPBENCH – 3.9

DOOM -10.71

Quake – N/A

SPEEDSYS – 9.20

Advertisements

11 Comments

  1. I had this same machine-bought it in 1993 at Sears for around 800.00–came without cdrom–had to buy the cd rom kit with speakers etc separately–I liked that machine but its lack of expandability and the fact I bought a pci open GL video card, the Hercules Stingray, made me purchase component and make my own. Soon after I pended a computer store and built all sorts of systems and spent a great deal of time playing with Linux. Now I’m way too busy to mess around with computers and basically just buy Mac from now on 🙂

  2. What kind of TAG Ram chip are you using in this system to get the 128K of Cache? I have the 32Kx8 SRAM chips but I cannot find a 32Kx8 TAG SRAM chip.

    • If memory serves me (I no longer have this particular PC) I just used 5 32×8 chips for 128kb of l2 cache. I didn’t use any special chip for the tag ram. as long as its the same speed or faster it should work.

      actually I think I used a 8k*8 chip for the Tag RAM.

        • Nathan T.
        • Posted July 23, 2015 at 16:12
        • Permalink

        Thank you so much for the information. So I can utilize an 8kx8 TAG RAM chip for 128K of Cache with no issues then? I just want to make certain as I have people telling me to make a comparator logic circuit and an adapter to plug in one of the 5 cache chips I bought.

      • I went back in my forum files and I still had the conversation saved with the guy I bought the chips off of. it was 4 32×8 chips and 1 8×8 tag ram. just put them in the board and set the jumper to 128kb and it should work fine. mine did at least.

        the official docs on the machine state “The chips may be 25ns, 20ns, or 15ns while the Tag SRAM can be either 20ns or 15ns. The Cache and TAG RAM are either 28-pin for 32KB or 128KB of cache, or 32-pin for 512KB of cache” so you could also possibly just use a regular 32kx8 chip and just be sure its 20 or 15ns and that may work fine as well.

  3. I actually tried that and Ram speed dropped from 19.3MB/Sec to 11.9MB/sec. The 8K l1 cache dropped from 60.4MB/Sec to 31.6MB/sec. very confusing.

    • that is strange. 8x8k sram is cheap enough that you can give it a try or you could try a 12ns rated 32×8 sram chip as tag ram. I wish I still had this machine to take a look for you. When I picked up my Tandy 425SX I replaced this one since that PC was basically the same thing but just better. let us know your results.

        • Nathan T.
        • Posted July 27, 2015 at 08:59
        • Permalink

        Well the cache chips I purchased are rated at 12ns already. There is a company that still makes Tag-cache chips and I’ve tried contacting their distributor to see if I can purchase some, but I have yet to hear back. Interestingly enough a friend of mine who is also an avid old computer user told me that all of his Packard Bell computers from this era slowed down horribly when he used cache without a TAG chip. Even though it technically still booted properly. Once it’s working properly I should see speeds of double what I am getting from what I have been told. I wouldn’t know personally. All the machines I owned after this one by default had l2 cache installed and configured.

      • do you have any benchmark results with/w out the l2 cache? http://www.philscomputerlab.com/486-benchmark-suite.html has a good little package of DOS benchmarks I use.

  4. I use that same bench. Without L2 Cache enabled I get 61.4MB/s on the L1 with RAM pulling 19.1MB/s for the speed. Once I installed the L2 Cache I get 32.4MB/s on the L1 and 24.4MB/s for L2 and RAM pulls 11.8MB/s. It seems without that Comparator Logic circuit designed to lay out the word table for the L2 Cache it slows the system read speed down immensely.

    • to be honest I don’t think I actually timed my l2 cache so for all i know it was doing the same as yours. you would have to check our benches for Doom and Quake to see if mine was running better. If mine was performing better I’m guessing its the use of the 8x8k tag ram


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Waltorious Writes About Games

Game-related ramblings.

NekoJonez's Gaming Blog

Thank you for your visit!

Old School Game Blog

Amiga enthusiasm, retro gaming passion

Evelynn Star

Lynn talks about video games, records and books ...

Retro Megabit

Sharing My Retro Video Game Collection.

133MHz's Junk Box

Random electronics and gaming crap

SNES A Day

Every game, every day

Too Many Games

A blog talking about games

Retrocosm's Vintage Computing, Tech & Scale RC Blog

Random mutterings on retro computing, old technology, some new, plus radio controlled scale modelling.

The PewPew Diaries.

Work(s) in Progress!

The Martian Oddity

Video Games and other weird stuff!

1001Up

1001 video games and beyond

retro computing and gaming plus a little more

sparcie

retro computers and stuff

jispylicious

Stay Jispy!

lazygamereviews

MS-DOS game reviews, retro ramblings and more...

%d bloggers like this: