Date: Thursday, 22 November 1984 From: Jesse Eaton To: Osborne Exec users Re: IEEE-488/CENTRONICS on OSBORNE The following diagram should allow you to connect the OSBORNE EXECUTIVE'S IEEE-488 port to a CENTRONICS port: IEEE-488 CENTRONICS 1 ------- DATA0 (LSB) -----> 2 2 ------- DATA1 -----------> 3 3 ------- DATA2 -----------> 4 4 ------- DATA3 -----------> 5 13 ------- DATA4 -----------> 6 14 ------- DATA5 -----------> 7 15 ------- DATA6 (MSB)------> 8 16 ------- DATA7 (PAR) -----> 9 6 ------- STROBE* ---------> 1 12 ------- GROUND ----------> 19 8 <------ BUSY ------------- 11 NOTE: STROBE IS NORMALLY NEGATIVE GOING PULSE. BUSY LINE IS HIGH WHEN PRINTER IS BUSY. THERE ARE PULLUP RESISTORS ON THE IEEE-488 WHICH PULL THIS LINE HIGH IF THE CABLE IS UNPLUGGED OR IS WIRED INCORRECTLY. GOOD LUCK AND LET ME KNOW HOW IT TURNS OUT. I STILL HAVE TO REWIRE MY CABLE AS I TOO USED THE DIAGRAM ON PAGE 445 IN THE SYSTEM REFERENCE MANUAL. WE "ALL" KNOW THAT IS OUT TO LUNCH. Jesse (all for better, more correctter documintasion) Eaton. Date: Friday, 23 November 1984 From: Ronald Blanford To: Jesse Eaton Re: IEEE-488/CENTRONICS on OSBORNE The IEEE 488 to Centronics wiring diagram you gave works like a charm. There's still one minor problem unrelated to the wiring, and that's that the Executive's BIOS times out occasionally when the printer is busy and thinking that it's nonexistent asks if you want to deassign it. Answering "no" lets you continue just fine, but this is a nuisance because it occurs quite often with my slow letter-quality printer. The timeout delay should be patchable, but I haven't looked enough to find it yet. Thanks, Ron Date: Friday, 23 November 1984 From: Jesse Eaton To: All Osborn Exec users Re: OSBORNE EXECUTIVE PRINTER TIMEOUTS The most recent version of the Osborne Executive Bios is V1.1. It allows you to set the timeout value for printers. The SETUP.COM program was also modified to reflect this. Jesse (hacker isn't a dirty word) Eaton Date: Friday, 23 November 1984 From: Jesse Eaton To: All Osborn Exec users Re: OSBORNE EXECUTIVE IEEE-488 PORT The IEEE-488 port on the OSBORNE EXECUTIVE can be configured via a PIA chip to communicate using the CENTRONICS or IEEE protocol to talk to devices connected on that port. If you plan on doing any serious hardware hacking using it I would highly recommend the five manual Technical Reference set. They contain BIOS and ROM listings for V1.1 as well as tutorials on the schematics and chip sets. The price is steep however. $125 + $18 (S&H). Jesse (the librarian) Eaton