Plus2 was the second chapter on
MICROCode Consulting monitor ROM and BIOS upgrades. A complete
replacement for the Xerox 820-II or Xerox 820-I/BigBoard
sporting the Emerald Microware disk drive extender plug-in,
Plus2 offered enormous improvements over the
OEM monitor and BIOS. Using a similar design as its parent, SmartROM,
Plus2 supported multiple drive formats
and even a hard disk.
Written in Z-80 assembler for use under QP/M, CP/M 2.x and compatibles, features of Plus2 include:
- fully upward-compatible with original Xerox 820-I and BigBoard-I BIOS
- powerful resident monitor with 17 commands
- handles both 5.25" and 8" drives in a single package, including full motor control
- intrinsic support for 19 different single-sided and double-sided 5.25" and 8" disk formats
- access to over 100 disk formats via P2DSKDF utility
- auto-detection of quad drives
- automatic boot of operating system when disk is present
- real-time clock for use with operating systems that support it such as QP/M
- supports the same ADM-31 video ESCape sequences available on Xerox 820-II and Kaypro computers
- automatic screen blanking after 15 minutes of screen & keyboard inactivity (Xerox 820-I only)
- Ferguson RAMcard support
- optional screen display of time
- 7-bit or 8-bit keyboard operation
- screen dump to printer with single keystroke
- special ABORT and PAUSE keys (user-definable)
Downloads
| Package | Version | Date | Size (bytes) | Download time (28.8K baud) |
Click to download |
| 2.5MHz Xerox keyboard ROMs | 0.2a | Mar 1986 | 3802 | 2sec | p2x25.zip |
| 4.0MHz Xerox keyboard ROMs | 0.2a | Mar 1986 | 3802 | 2sec | p2x40.zip |
| 2.5MHz generic keyboard ROMs | 0.2a | Mar 1986 | 3802 | 2sec | p2g25.zip |
| 4.0MHz generic keyboard ROMs | 0.2a | Mar 1986 | 3802 | 2sec | p2g40.zip |
| Plus2 software | 0.2 | Mar 1986 | 71k | 26sec | plus2.lbr |
| Plus2 documentation (updated) | 0.2 | Nov 2004 | 340k | 2min 5sec | plus2.pdf |
| Plus2 software and documentation | 0.2 | Nov 2004 | 318k | 1min 56sec | plus2.zip |
Installation
Installation of this package entails the following steps:
- Burn the "A" and "B" ROM images onto two 2716 EPROMs and then replace the "A" and "B" ROM chips prominently located in two adjacent sockets on the motherboard. Upon power-up, you should immediately see a sign-on message. If you accidentally reverse the order and plug the EPROMs into the wrong ROM socket, nothing will work but your computer will not be damaged. (Conversely, plugging in the EPROMs upside down could damage your motherboard.)
- Installation of the software package entails running NULU on your CP/M or QP/M system and extracting the files to your system to some drive/user area, likely drive A, user 0 as this is operating system software including a new operating system BIOS.
- Although not required, follow the directions given with your QP/M or CP/M operating system for replacing the BIOS in the operating system boot image. You may be unable to use some of the features offered by this package such as date/time stamping and multiple drive support if you do not replace your BIOS.
This is restricted for personal use software that is provided without any warranty whatsoever as described in the legacy Z-80 home page.