PATCHING PERFECT CALC v1.10 FOR KAYPROs WITH GRAPHICS MONITORS by Bob Stein 3-3-88 Perfect Calc was bundled with many of the earlier Kaypros, before the advent of the monitor capable of displaying reverse video. Many of the original owners of Kaypro IIs went on to 4s and 10s, yet continued to use Perfect Calc. Unfortunately, there was no way to utilize the reverse video because Kaypro disabled the terminal-configuration routine in the version of PCCONFIG.COM that they supplied. However, it is possible to patch Perfect Calc to display the axes in reverse video, and to make the cursor (cell marker) a reverse video block instead of < >, using DDT. Be sure that you have a backup copy of PC.OVL, which is the file that must be patched, just in case! Since this patch will work only with version 1.10 of Perfect Calc, check the version you are using by loading PC; note the version number in the sign-on message which appears before the cells are displayed. If it is not VERS 1.10, stop and forget the whole thing! To start, put your Perfect Calc program disk in drive A and a disk containing DDT.COM in drive B. Log onto drive A and perform the following steps: You Enter Computer Displays Remarks --------- ----------------- ------- B:DDT PC.OVL DDT VERS 2.2 NEXT PC 8600 0100 - - is the DDT prompt S844A 844A 00 1B 844B 00 42 844C 00 30 844D 00 1B 844E 00 42 844F 00 31 8450 00 8451 00 8452 00 8453 00 8454 00 1B 8455 00 43 8456 00 30 8457 00 1B 8458 00 43 8459 00 31 845A 00 . - Type a period and Ctrl-C Warm Boot A> or A0> SAVE 133 PC.OVL Delete File? Y A> or A0> If you have followed the preceding instructions to the letter, the next time you use Perfect Calc you will have the cell axes and a block cursor in half-intensity reverse video.