For CP/M, programs exited via a jump to 0. DOS calls were made to location 5. The 8259 interrupt controller uses call instructions, so I'm not sure which devices use the RST instructions for interrupts. The 8085 has 4 interrupt lines, tied to RST 4.5, 5.5, 6.5, 7.5. RST 4.5 was considered a "trap".swty todd said:we were taught that RST 1 stands for Return to command mode. What's up with this location 8 thing?
ARHL MACRO ;ARITH RIGHT SHIFT HL
DB 10H
ENDM
DSUB MACRO ;HL=HL-BC
DB 08H
ENDM
JNXC MACRO X ;JMP IF NOT X CARRY (INX, DCX)
DB 0DDH
DW X
ENDM
JXC MACRO X ;JMP IF X CARRY
DB 0FDH
DW X
ENDM
LDHI MACRO I ;DE=HL+I
DB 28H
DB I
ENDM
LDSI MACRO I ;DE=SP+I
DB 38H
DB I
ENDM
LHLX MACRO ;HL=(DE)
DB 0EDH
ENDM
RDEL MACRO ;ROTATE DE,CY LEFT
DB 18H
ENDM
RIM MACRO ;RESET INT MASK
DB 20H
ENDM
RSTV MACRO ;RST IF V SET TO 40H
DB 0C8H
ENDM
SHLX MACRO ;(DE)=HL
DB 0D9H
ENDM
SIM MACRO ;SET INT MASK
DB 30H
ENDMNo. I have both pinouts here. And they are definately not the same.Jeff Reid said:The 8085 is pin compatable with 8088,
If you change the processor and the BIOS and write your own hardware access, I would not think that it is a 8085 system anymore. It is an 8086 system. It would be easier to buy an old PC to run MSDOS applications.an 8085 system could be converted to run MSDOS or CP/M-86
Jeff Reid said:8085 ... 8088 pinout
I checked on this and your right. I corrected my previous post. Based on a project I worked on, the timing was the same or close enough that the existing Intel peripheral chips for the 8080-8085 would also work with the 8088. I worked for Pertec Computersimbad said:No. I have both pinouts here. not the same.
Note that in 8086 mode, the index is sent in response to a second INTA (interrrupt acknowledge) from the cpu. If I remember correctly (which I'm starting to doubt now), the early 8259 output a 2 byte "INT" instruction. The first INTA from the cpu caused the 8259 to output a hex CD on the bus and the second INTA from the cpu cause the 8259 to output the immediate byte value (index). I don't remember if the "CD" was a programmable value or hard coded into the 8259. It's gone now or at least undocumented, but the index from the 8259 still isn't sent until a second INTA is received, so that much of the legacy handshake remains.The 8259 has two different modes. One where it send the call instruction with an address, this is for 8080/8085 CPUs and one where it sends only an Index into the interrupt vector table. This is used for 8086 CPUs.
The 8088 and later cpus use the single byte INT3 instruction for the same purpose.The RST instruction maybe used to make different calls to different subsystems. It is easy to replace a single byte with this one-byte instruction to interrupt the execution and branch to a debugger. This way you can set breakpoints in your application.
Atari? The Atari 400/800/65XE/130XE systems ran on 2mhz Motorola 6502 (twice as fast as an Apple II). The Atari ST and early Mega ST systems ran on 8mhz Motorola 68000.As far as I know Atari did so in their TOS.
As mentioned above, it was done with an adapter board, allowing the rest of the hardware in that system to be the same (except that the BIOS chip was programmed with 8088 code.If you change the processor and the BIOS and write your own hardware access, I would not think that it is a 8085 system anymore. It is an 8086 system. It would be easier to buy an old PC to run MSDOS applications.
After more research on this, it's just easier to make an adaptor for the 8085. The layouts are different, but both 8085 and 8088 use a single 5 volt source, and share data and the lower 8 bits off address on the same pins (unlike the 8080), and the timing is the same or close enough to work with supporting chip sets. I recall that the PCC 2000 already had some hardware to bank in more than 64k of memory, and the adaptor board converted pinouts for A16-> A19 to a second mini-adaptor board that plugged into a chip socket(s?) to replacing the banking logic that was used with the 8085.The 8085 is pin compatable with 8088
An 8085 program refers to a set of instructions written in assembly language that can be executed by an Intel 8085 microprocessor. The 8085 is a popular microprocessor used in many electronic devices such as calculators, microwave ovens, and industrial control systems.
An 8085 program is used to control the operations of a microprocessor and perform specific tasks such as data processing, logic operations, and input/output operations. It is commonly used in embedded systems to control electronic devices and in educational settings to teach assembly language programming.
An 8085 program is written in assembly language, which is a low-level programming language that uses mnemonic codes to represent machine instructions. These instructions are then converted into binary code, which can be executed by the microprocessor. Assembly language programming requires a good understanding of the 8085 microprocessor architecture and its instruction set.
An 8085 program consists of three main components: labels, mnemonics, and operands. Labels are used to mark specific locations in the program, mnemonics represent the instructions to be executed, and operands provide data or memory addresses required for the instruction. These components work together to form a sequence of instructions that the microprocessor can understand and execute.
Due to its low cost, simplicity, and versatility, the 8085 microprocessor is used in a wide range of applications such as industrial control systems, traffic light controllers, home appliances, and electronic toys. It is also commonly used in educational settings to teach students about microprocessors and assembly language programming.