Continued from previous post, overview & background on the Compaq Portable 486 <<<
Setting up the Compaq Portable 486 is a bit of a hassle similar to the Compaq Portable 386 – it does not have a BIOS – meaning that it relies on a floppy-based program to make configuration changes. These settings are stored by a Dallas RTC chip, which usually will have run flat by 2019. Fortunately, the Dallas RTC chip is socketed (unlike the Compaq clamshell SLT series), meaning it can be easily replaced. However, what is not so easy is running the setup program – which is mandatory to run after swapping out the RTC chip. Without running setup, you will be presented with error codes, and the computer won’t boot to MS-DOS.
Downloading the software and creating a boot disk was a nightmare as there are not that many of these computers still around, meaning that there were not that many posts online about which program (Softpaq) to use to generate the disk.
Using the software is also not easy – I feel that these Softpaqs were developed for the dealer to set up the computer and not intended for the end-user. When in the setup program, make sure you pick a hard disk to use from the list of drives – the custom disk geometry option does not work – it won’t allow you to save the settings if you try (at least with my unit!)
For Windows 95 you have to disable or change the generic resources of the SCSI CDROM in the setup, else you get BSODs (some sort of conflict between the hard disks and the on-board SCSI CDROM controller)
You will need to open your Compaq Portable 486 to access a bank of switches, one of which is used to clear or save the EISA configuration, see the maintenance manual PDF here.
Next Post: Games & Benchmarks on the Compaq Portable 486 >>> (coming soon)