The MCS-48 series is a forerunner of the MCS-51. There are some noteable differences, which you will quickly encounter when you read the datasheets for the MCS-48 and compare with the MCS-51 series.

Primary differences, aside from the on-board resources, are the instruction set, which includes I/O instructions for the MCS-48, which are absent in the MCS-51. Aside from that, the assertion made early-on by Intel was that the two are source-code compatible (aside from I/O and a very few other instructions). Therefore, if you download one of several freeware MCS-48 disassemblers, you can disassemble the object code, find the incompatible instructions, and, purportedly, reassemble the code for the MCS-51 family member. One of the modes in which the 805x timers work is compatibl with the 8048, but, it will require that you ensure it is properly configured, which is not needed in the 8048. If you carefully read and compare the datasheets, the steps you'll have to take will become apparent.

One tool which will be handy if you want it is Michael McCarrick's (www.acebus.com) 8048.EXE, which is an integrated development environment for DOS, for the 8048-series. It includes a pretty good simulator, at least at a functional level, which will allow you to observe what the existing source code, once you have it, does within the MCU. It also allows you to edit and assemble your 8048 code. That may, in fact, help prepare you for the next step.


Good Luck!

RE