Difference between revisions of "MicroVAX 3800/3900"
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| − | The '''MicroVAX 3800''' and '''MicroVAX 3900''' are very similar, the only distinction being the enclosure and accompanying [[disk drive]]s: the 3800 was available in the [[BA213]], and the 3900 in the [[H9644 cabinet]]. The MicroVAX 3900 includes an [[RA90]]. They both used the [[KA655 CPU]]. | + | The '''MicroVAX 3800''' and '''MicroVAX 3900''' are very similar, the only distinction being the enclosure and accompanying [[disk drive]]s: the 3800 was available in the [[BA213]], and the 3900 in the [[H9644 cabinet]]. The MicroVAX 3900 includes an [[RA90]]. |
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| + | They both used the [[KA655 CPU]], so both are built around the [[QBUS]], which was used only for [[input/output|I/O]]; [[main memory]] used the [[KA650 Main Memory System]], using a special [[bus]] carried on [[over the back]] connectors as well as the [[CD interconnect]] of the QBUS backplane. (The [[address space]] of the [[QBUS]] was limited to 4MB, and the data section is only 16 bits wide.) | ||
There were special [[VAXserver]] versions, for usage in [[Local Area VAXcluster]]s, named '''VAXserver 3800''' and '''VAXserver 3900'''. The difference between these and the MicroVAXen is in the system ROM on the [[Central Processing Unit|CPU]] board, which prevents multi-user access to these computers. | There were special [[VAXserver]] versions, for usage in [[Local Area VAXcluster]]s, named '''VAXserver 3800''' and '''VAXserver 3900'''. The difference between these and the MicroVAXen is in the system ROM on the [[Central Processing Unit|CPU]] board, which prevents multi-user access to these computers. | ||
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[[Category: DEC VAX systems]] | [[Category: DEC VAX systems]] | ||
| + | [[Category: QBUS VAXen]] | ||
[[Category: VAXservers]] | [[Category: VAXservers]] | ||
Revision as of 06:06, 31 January 2024
| MicroVAX 3800/3900 | |
| Summary | |
|---|---|
| Announcement date: | 10 April 1989 |
| Codename: | Mayfair III |
| OS support (VMS): | V5.1 |
| CPU Details | |
| CPU name (VMS): | KA655 |
| CPU name (console): | KA655 |
| CPU module: | KA655 |
| Module: | M7625 |
| Number of processors: | 1 |
| VMS DCL CPU: | 10 |
| VMS DCL XCPU: | 1 |
| SID: | 0A000005 |
| XSID: | 01530301 |
| CPU chip: | CVAX |
| FPU chip: | CFPA [1] |
| CPU technology: | CMOS |
| CPU cycle time: | 60ns [1] |
| CPU clock: | 33MHz [1] |
| Instruction-buffer: | 12 bytes [1] |
| Translation-buffer: | 28 entries [1] |
| Cache: | 1KB [1] |
| Backup cache: | 64KB (120ns) [1] |
| Compatibility mode: | No |
| Console processor: | CPU |
| Console device: | None |
| Firmware version: | V5.3 |
| Memory | |
| Minimum memory: | 16MB |
| Maximum memory: | 64MB |
| Memory checking: | 7-bit ECC/longword [1] |
| I/O | |
| Q-bus: | 1 @ 3.3MB/s |
| LAN support: | optional |
| Performance | |
| VUPs: | 3.8 [2] |
| SPECmarks: | 4.0 |
The MicroVAX 3800 and MicroVAX 3900 are very similar, the only distinction being the enclosure and accompanying disk drives: the 3800 was available in the BA213, and the 3900 in the H9644 cabinet. The MicroVAX 3900 includes an RA90.
They both used the KA655 CPU, so both are built around the QBUS, which was used only for I/O; main memory used the KA650 Main Memory System, using a special bus carried on over the back connectors as well as the CD interconnect of the QBUS backplane. (The address space of the QBUS was limited to 4MB, and the data section is only 16 bits wide.)
There were special VAXserver versions, for usage in Local Area VAXclusters, named VAXserver 3800 and VAXserver 3900. The difference between these and the MicroVAXen is in the system ROM on the CPU board, which prevents multi-user access to these computers.
The MicroVAX 3900 is the original model of VAX emulated by SIMH. (It now also emulates a VAX-11/780.) It can run 4.3 BSD, VMS 5.1-1 to 7.3, and NetBSD, and OpenVMS 7.3 under Debian on a Tinkerboard.
References
External Links
- 3800 - documentation at Bitsavers
- MicroVAX 3800 VAXserver 3800 Installation (EK-164AA-IN-001)
- MicroVAX 3800 VAXserver 3800 Operation (EK-16SAA-OM-001)
- MicroVAX 3900 VAXserver 3900 Operation (EK-168AA-OM-001)
| v • d • e VAX Computers and Operating Systems |
|---|
| VAX-11/7xx (including VAX 86x0) - VAX-11/780 • VAX-11/785 • VAX-11/750 • VAX-11/730 • VAX 8600 • VAX 8650
VAX 8000 series (excluding VAX 86x0, above) - VAX 82xx/83xx series • VAX 85xx/87xx/88xx series MicroVAXen (many types also come in VAXserver and VAXstation models) - MicroVAX I • MicroVAX II VAXstation Series - VAXstation I • VAXstation II Late Model VAXen - VAX 4000 series • VAX 6000 series • VAX 7000 series • VAX 9000 series • VAX 10000 series |
| Special Purpose VAXen - VAXft series • rtVAX series • Infoserver series
Clones - CM 1700 • TPA-11/580 |
