Difference between revisions of "MA780 Multiport Memory Option"
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The '''MA780 Multiport Memory Option''' was a [[Metal Oxide Semiconductor|MOS]] [[Dynamic RAM|DRAM]] [[multi-port memory]] [[main memory]] system for the [[VAX-11/780]]; it allowed creation of [[multi-processor]] systems such as the [[VAX-11/782]]. It was 64 [[bit]]s wide, to interface to the -11/780's [[Synchronous Backplane Interconnect]] (SBI), and provided [[error-correcting code|ECC]] (8 bits/double-[[word]]), which could correct all single-bit errors. | The '''MA780 Multiport Memory Option''' was a [[Metal Oxide Semiconductor|MOS]] [[Dynamic RAM|DRAM]] [[multi-port memory]] [[main memory]] system for the [[VAX-11/780]]; it allowed creation of [[multi-processor]] systems such as the [[VAX-11/782]]. It was 64 [[bit]]s wide, to interface to the -11/780's [[Synchronous Backplane Interconnect]] (SBI), and provided [[error-correcting code|ECC]] (8 bits/double-[[word]]), which could correct all single-bit errors. | ||
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+ | [[File:Huge_4_VAX-11-780_MA780_System.png|thumb|right|400px|Huge system made up of four VAX-11/780's connected to an MA780 Multiport Memory]] | ||
An MA780 system was comprised of: | An MA780 system was comprised of: | ||
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<!-- It was possible to [[interleaving|interleave]] two MA780's to improve performance. --> | <!-- It was possible to [[interleaving|interleave]] two MA780's to improve performance. --> | ||
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==Implementation== | ==Implementation== | ||
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| 8 || M8210 || MAP || Memory Array | | 8 || M8210 || MAP || Memory Array | ||
|- | |- | ||
− | | 9 || | + | | 9 || M8210 || MAP || Selective Map Cache (optional) |
|- | |- | ||
| 10 || M8261 || MPS || Multiport Port Synchronizer | | 10 || M8261 || MPS || Multiport Port Synchronizer | ||
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* [http://www.bitsavers.org/pdf/dec/vax/780/EK-VAXV2-HB-002_VAX_Maintenance_Handbook_VAX-11_780_1983_Edition_198303.pdf VAX Maintenance Handbook VAX-11/780 1983 Edition] (EK-VAXV2-HB-002) - the MA780 is covered on pp. 235-253 | * [http://www.bitsavers.org/pdf/dec/vax/780/EK-VAXV2-HB-002_VAX_Maintenance_Handbook_VAX-11_780_1983_Edition_198303.pdf VAX Maintenance Handbook VAX-11/780 1983 Edition] (EK-VAXV2-HB-002) - the MA780 is covered on pp. 235-253 | ||
− | * [http://www.bitsavers.org/pdf/dec/vax/780/EK-SI780-IN-002_VAX-11_780_Installation_Manual_198201.pdf VAX-11/780 Installation Manual] (EK-SI780-IN-002) - the MA780 is covered in Chapter 9 | + | * [http://www.bitsavers.org/pdf/dec/vax/780/EK-SI780-IN-002_VAX-11_780_Installation_Manual_198201.pdf VAX-11/780 Installation Manual] (EK-SI780-IN-002) - the MA780 is covered in Chapter 9 (on pp. 71-122 of the PDF) |
[[Category: VAX Memories]] | [[Category: VAX Memories]] | ||
+ | [[Category: SBI]] |
Latest revision as of 14:56, 15 May 2024
The MA780 Multiport Memory Option was a MOS DRAM multi-port memory main memory system for the VAX-11/780; it allowed creation of multi-processor systems such as the VAX-11/782. It was 64 bits wide, to interface to the -11/780's Synchronous Backplane Interconnect (SBI), and provided ECC (8 bits/double-word), which could correct all single-bit errors.
An MA780 system was comprised of:
- the main MA780 unit, which contained a custom backplane holding i) a small group of control cards, and ii) a variable number of array cards (between 1 and 8 per MA780), holding the DRAM chips; and
- in each connected CPU (between 2 and 4), an MA780-C Port Interface, held in another, smaller custom backplane, which connected the main MA780 unit (up to two different ones per MA780-C) to the host CPU's SBI.
With the 256-Kbyte M8210 array card (shared with the MS780-C), this allowed a maximum of 2MB per MA780. The -11/780 thus supported up to 2 MA780 subsystems, for a maximum of 4MB with fully populated MA780's.
Implementation
The main MA780 was implemented on super hex cards, mounted in a custom 20-slot backplane. The cards were:
Slot | Board | Acronym | Function |
---|---|---|---|
1 | M8210 | MAY | Memory Array (optional) |
... | |||
8 | M8210 | MAP | Memory Array |
9 | M8210 | MAP | Selective Map Cache (optional) |
10 | M8261 | MPS | Multiport Port Synchronizer |
11 | M8212 | MDT | Memory Data Paths |
12 | M8260 | MAT | Multiport Array Timing |
13 | M8259 | MPC | Multiport Port Control (Port 3 - optional) |
14 | M9045 | BDI Connect (rear) | |
15 | M8259 | MPC | Multiport Port Control (Port 2 - optional) |
16 | M9045 | BDI Connect (rear) | |
17 | M8259 | MPC | Multiport Port Control (Port 1) |
18 | M9045 | BDI Connect (rear) | |
19 | M8259 | MPC | Multiport Port Control (Port 0) |
20 | M9045 | BDI Connect (rear) |
Slots 1-8 held 256-Kbyte M8210 array cards; a minimum of one, in slot 8, was required.
The MA780-C was mounted in a custom 20-slot backplane. The contents were:
Slot | Board | Acronym | Function |
---|---|---|---|
1 | Blank | ||
2 | M9040/M8258 | SBI Terminator / Multiport Port Interface (optional) | |
3 | M8258 | Multiport Port Interface | |
4 | M9045 | BDI Connect (rear) |
External links
- VAX Maintenance Handbook VAX-11/780 1983 Edition (EK-VAXV2-HB-002) - the MA780 is covered on pp. 235-253
- VAX-11/780 Installation Manual (EK-SI780-IN-002) - the MA780 is covered in Chapter 9 (on pp. 71-122 of the PDF)