US5812820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Virtual UART
Assignee: PACIFIC COMMWARE
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Filing: 1995-09-29
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Granted: 1998-09-22
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Expires: 2015-09-29
Abstract
Abstract The present invention is a computer operating system method for allowing applications running in Virtual Machines, including but not limited to DOS applications, making direct UART I/O accesses under Windows for Workgroups™ or Windows 95™ operating systems to access VCOMM port drivers installed in the system. The invention involves the steps of: (1) receiving from the application instructions for a UART; (2) simulating a UART by returning to the application simulations of the responses of a UART; (3) translating the instructions for a UART into instructions for VCOMM; (4) sending the translated instructions to VCOMM; receiving responses from VCOMM; (5) translating the responses from VCOMM intosimulated responses from a UART; and (6) transmitting the simulated responses from a UART to the application.
Inventors
- 👤 John S. H. Loram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:20
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/44; G06F9/455; G06F9/45533; G06F9/45537
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A computer operating system method for allowing applications running in Virtual Machines making direct UART I/O accesses under Windows for Workgroups™ or Windows 95™ operating systems to access VCOMM port drivers installed in the system comprising the steps of: a) receiving from the application instructions for a UART; b) simulating a UART by returning to the application simulations of the responses of a UART; c) translating the instructions for a UART into instructions for VCOMM; d) sending the translated instructions to VCOMM; e) receiving responses from VCOMM; f) translating the responses from VCOMM into simulated responses from a UART; and g) transmitting the simulated responses from a UART to the application.
Claim 2
Dependent Claim
111 words
A computer operating system method for allowing applications running in Virtual Machines making direct UART I/O accesses under Windows for Workgroups™ or Windows 95™ operating systems to access VCOMM port drivers installed in the system comprising the steps of: a) receiving from the application instructions for a UART; b) simulating a UART by returning to the application simulations of the responses of a UART; c) translating the instructions for a UART into instructions for VCOMM; d) sending the translated instructions to VCOMM; e) receiving responses from VCOMM; f) translating the responses from VCOMM into simulated responses from a UART; and g) transmitting the simulated responses from a UART to the application.
Claim 3
Dependent Claim
54 words
The method described in claim 1, further including the sub-step of simulating all 8 UART registers by creating in a memory 8 fields for receiving and storing instructions from an application running in a Virtual Machine making direct UART I/O accesses wherein each field corresponds to one of the 8 registers in a UART.
Claim 4
Dependent Claim
18 words
The method described in claim 1, further comprising the step of: h) managing contentions between UART based devices.
Claim 5
Dependent Claim
27 words
The method described in claim 2, wherein the sub-step of simulating UART registers includes simulating the FIFO buffers of the 16550 UART and the UART Scratch register.
Claim 6
Dependent Claim
20 words
The method described in claim 1, wherein the step of simulating a UART includes simulating a UART's diagnostic test mode.
Claim 7
Independent Claim
71 words
A method for improving performance in a computer operating system implementing a virtual UART to communicate with a VCOMM port driver running under Windows for Workgroups™ or Windows 95™ operating systems comprising the steps of: a) accumulating characters written to the virtual UART in a holding register; b) calling the VCOMM -- WriteComm Procedure when said holding register is full; and c) transmitting said accumulated characters to the VCOMM port driver.
Claim 8
Independent Claim
71 words
A method for improving performance in a computer operating system implementing a virtual UART to communicate with a VCOMM port driver running under Windows for Workgroups™ or Windows 95™ operating systems comprising the steps of: a) accumulating characters written to the virtual UART in a holding register; b) calling the VCOMM -- WriteComm Procedure when said holding register is full; and c) transmitting said accumulated characters to the VCOMM port driver.
Claim 9
Dependent Claim
68 words
The method of claim 6, wherein, to prevent data from remaining in a partially full holding register for a protracted length of time, said step of accumulating characters is limited to a predetermined length of time and, if such length of time is reached before said holding register is full, the VCOMM -- WriteComm Procedure is called and said accumulated characters are delivered to the VCOMM port driver.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-21 | 2002-03-23 | 2002-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-21 | 2006-03-23 | 2006-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-21 | 2010-03-23 | 2010-09-22 | $7700.00 | Window Closed / Lapsed |