ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» º º º ISA Bus: Above Board Technical Information º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ PARALLEL PORT PARALLEL PORTS DOS assigns the names LPT1, LPT2, and LPT3 to parallel ports according to the number of parallel ports in the computer and the I/O address each uses. You can have up to three parallel ports in your computer only if LPT1 is on the IBM Monochrome display Adapter or its equivalent. Otherwise DOS limits your computer to two parallel ports (LPT1 and LPT2). When you turn on or restart your computer, DOS checks for parallel ports first at I/O address 3BC, then at 378, and finally at 278. The first port it finds becomes LPT1, the second LPT2, and the third LPT3. The SETBOARD program lets you name the Above Board's port. You can't set the Above Board port to I/O address 3BC. This address is reserved for video boards that contain a parallel port. If you have only one parallel port in the computer, DOS always names it LPT1, regardless of the I/O address it uses. If you have two parallel ports, DOS assigns LPT1 to the port using the highest address. SERIAL PORT GENERAL NOTES The AB uses the standard IBM AT 9-pin serial connector. Other 9-pin connectors will not work. Our serial port will not work in the current loop mode. DOS Versions through 3.2 support COM1 and COM2 only. DOS 3.3 supports COM3 and COM4 only on machines whose BIOS can detect the 3rd and 4th serial ports. (So far, only IBM PS-2 Models 50, 60 & 80 can do this). Should set COM1 at 3F8 and COM2 at 2F8 unless customer has special communications software that can recognize serial ports at 3E8 and 2E8. The AB serial port uses the Intel 82510 chip. The IBM Advanced diagnostics is looking for an older serial port chip so the AB Serial Port will fail the IBM Advanced Diagnostics. The only way to test the port is to use a serial device such as a mouse or modem on it. SERIAL PORT & INTERRUPTS ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³ Above Board ³ Interrupts ³ ³ Serial Port ³ ³ ÆÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍØÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͵ ³ COM 1 (3F8) ³ IRQ 4 ³ ³ COM 2 (2F8) ³ IRQ 3 ³ ³ COM 3 (3E8) ³ IRQ 2 or IRQ 5 ³ ³ COM 4 (2E8) ³ IRQ 5 or IRQ 2 ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ In Classic bus computers, there is no set convention for choosing the interrupt for COM3 and COM4. ACCESS TIMES FOR THE AB 286, AB PLUS, & PLUS 8 8088- and 8086-based computers ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³ Frequency ³ Bus Clock ³ Memory ³ I/O ³ ³ ³ Period ³ Cycle time ³ Cycle Time ³ ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´ ³ 4.77 MHz ³ 210 ns ³ 840 ns ³ 1050 ns ³ ³ ³ ³ ³ ³ ³ 8.0 MHz ³ 125 ns ³ 500 ns ³ 625 ns ³ ³ ³ ³ ³ ³ ³ 10.0 MHz ³ 100 ns ³ 400 ns ³ 500 ns ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ 80286- and 80386-based computers ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄ¿ ³ Memory Range³ 6 MHz ³ 8 Mhz ³ 10 Mhz ³ 12.5 Mhz³ ³ accessed ³ ³ ³ 120ns 150ns ³ ³ ÆÍÍÍÍÍÍÍÍÍÍÍÍÍÍØÍÍÍÍÍÍÍØÍÍÍÍÍÍÍØÍÍÍÍÍÍÍÑÍÍÍÍÍÍÍÍØÍÍÍÍÍÍÍÍ͵ ³ Conventional ³ ³ ³ ³ ³ ³ ³ and Extended ³ ³ ³ ³ ³ ³ ³ 16 => 16 ³ 501ns ³ 375ns ³ 300ns ³ 400ns ³ 334ns ³ ³ ³ 1ws ³ 1ws ³ 1ws ³ 2ws ³ 2ws ³ ÆÍÍÍÍÍÍÍÍÍÍÍÍÍÍØÍÍÍÍÍÍÍØÍÍÍÍÍÍÍØÍÍÍÍÍÍÍØÍÍÍÍÍÍÍÍØÍÍÍÍÍÍÍÍ͵ ³ Expanded ³ ³ ³ ³ ³ ³ ³ 8 => 8 ³ N/A ³ N/A ³ 600ns ³ 600ns ³ 501ns ³ ³ ³ ³ ³ 4ws ³ 4ws ³ 4ws ³ ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄ´ ³ 16 => 8 ³ N/A ³ N/A ³1200ns ³1200ns ³ 1002ns ³ ³ ³ ³ ³ 10ws ³ 10ws ³ 10ws ³ ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄ´ ³ 16 => 16 ³ 501ns ³ 375ns ³ N/A ³ N/A ³ N/A ³ ³ ³ ³ 1ws ³ ³ ³ ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÁ ws = wait states 8 => 8 8-bit bus operations to 8-bit devices. This takes sixty clock cycles, including four wait states (generated by the system board). 16 => 8 16-bit bus operations to 8-bit devices. Takes 12 clock cycles, including 10 wait states (generated by the system board). 16 => 16 16-bit bus operations to 16-bit devices. Takes three clock cycles including one wait state (generated by the system board). BYTE SWAPPING, MEMCS16, & AB 286 The Above Board 286, Plus, and Plus 8 work in computers with bus speeds of 6, 8, 10, and 12.5 MHz. Use the SETBOARD program to configure the Above Board for the proper speed. For the Above Board to work correctly, the computer must add at least one wait state to every memory access on the bus. Many computers eliminate wait states for accesses to system board memory, but these computers still add a wait state to access non-system board memory. IBM AT computers require this. Computers which do not add the wait state are not fully IBM AT compatible. Here's how the Above Board handles wait states for the different bus speeds: 6 and 8 MHz: MemCS16- works normally, (open-collector), 120ns for extended and conventional memory. In the C0000 and 150ns RAM D0000 segments, (expanded memory range), MemCS16- is actively driven hi or lo. It is driven hi if the bus address is not within the 64Kb page frame and it is driven lo if the address is within the page frame. The result of this is that the Above Board can be the ONLY 16-bit board in the C0000 thru D0000 segments, (UNLESS the 16BIT=xx parameter is included on the EMM.SYS device driver line). All other 8-bit boards will work correctly. 10 MHz, 120ns RAM: MemCS16- works normally (open-collector) for extended and conventional memory. In the C0000 and D0000 segments MemCS16- is left in the high-impedance state. This forces the motherboard to break 16-bit accesses into two 8-bit accesses, (each 8-bit access contains four wait states as the motherboard default), and the board reconstructs the data. We call this type of operation a byte-swap. No extra Wait states are added by the Above Board. 10 MHz, 150ns RAM: Same as above except that an extra wait state is added for all extended and conventional memory accesses. If the system is IBM compatible, the motherboard always inserts one wait state, so our extra wait state is actually the second. If people have "Zero- Wait State" machines, determine if the bus has the required wait state or if the bus is actually zero wait states. Our board requires at least one from the bus. No MemCS16- remains in high impedance state in the C0000 and D0000 segments. 12.5 MHz, both RAM speeds: An extra wait state is added for all extended and conventional memory accesses. Expanded memory is byte-swapped as described above. No MemCS16- remains in high impedance state in the C0000 and D0000 segments. NOTE: PC/XT systems do not use MemCS16 and therefore the Above Board 286 will keep the MemCS16 signal in high impedance for all above system types where applicable, (4.77 or 8MHz). EEPROM - HOW MANY TIMES CAN IT BE PROGRAMMED? The EEPROM on the Above Board is specified for 10,000 erase/write cycles per register. ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ End of file Intel FaxBack # 1010 December 2,1992